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Elavil (Amitriptyline HCl)
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Pharmacology
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Indications
Antidepressant
Antidepressant
Contraindications
In patients who have shown prior hypersensitivity to it. It should not be given concomitantly with a MAO inhibiting compound. Hyperpyretic crises, severe convulsions, and deaths have occurred in patients receiving tricyclic antidepressant and MAO inhibiting drugs simultaneously. When it is desired to substitute amitriptyline for a MAO inhibitor, a minimum of 14days should be allowed to elapse after the latter is discontinued. Amitriptyline should then be initiated cautiously with gradual increase in dosage until optimum response is achieved.
This drug is contraindicated in patients taking cisapride because of the possibility of adverse cardiac interactions including prolongation of the QT interval, cardiac arrhythmias and conduction system disturbances.
This drug is not recommended for use during the acute recovery phase following myocardial infarction and in the presence of acute congestive heart failure.
See Pregnancy under Warnings.
In patients who have shown prior hypersensitivity to it. It should not be given concomitantly with a MAO inhibiting compound. Hyperpyretic crises, severe convulsions, and deaths have occurred in patients receiving tricyclic antidepressant and MAO inhibiting drugs simultaneously. When it is desired to substitute amitriptyline for a MAO inhibitor, a minimum of 14days should be allowed to elapse after the latter is discontinued. Amitriptyline should then be initiated cautiously with gradual increase in dosage until optimum response is achieved.
This drug is contraindicated in patients taking cisapride because of the possibility of adverse cardiac interactions including prolongation of the QT interval, cardiac arrhythmias and conduction system disturbances.
This drug is not recommended for use during the acute recovery phase following myocardial infarction and in the presence of acute congestive heart failure.
See Pregnancy under Warnings.
Safety Information / Warning
Amitriptyline should be used with caution in patients with a history of seizures, impaired liver function, a history of hepatic damage or blood dyscrasias and, because of its atropine-like action, in patients with a history of urinary retention, or with narrow-angle glaucoma or increased intraocular pressure. In patients with narrow-angle glaucoma, even average doses may precipitate an attack.
There has been a report of fatal dysrhythmia occurring as late as 56hours after amitriptyline overdose.
Patients with cardiovascular disorders should be watched closely. Tricyclic antidepressant drugs, including amitriptyline, particularly when given in high doses, have been reported to produce arrhythmias, sinus tachycardia, and prolongation of the conduction time.
A few instances of unexpected deaths have been reported in patients with cardiovascular disorders. Myocardial infarction and stroke have also been reported with drugs of this class. Therefore, these drugs should be used with caution in patients with a history of cardiovascular disease, such as myocardial infarction and congestive heart failure.
Concurrent administration of amitriptyline and electroshock therapy may increase the hazards of therapy. Such treatment should be limited to patients for whom it is essential.
Close supervision is required when amitriptyline is given to hyperthyroid patients or those receiving thyroid medication.
Occupational Hazards: The drug may impair mental and/or physical abilities required for performance of hazardous tasks, such as operating machinery or driving a motor vehicle.
Pregnancy: There are no well-controlled studies in pregnant women; therefore, in administering the drug to pregnant patients or women who may become pregnant, the potential benefits must be weighed against the possible hazards to mother and child.
Lactation: Amitriptyline is detectable in breast milk. Because of the potential for serious adverse reactions in infants from amitriptyline, a decision should be made whether to discontinue nursing or discontinue the drug.
Children: In view of the lack of experience with the use of this drug in the treatment of depression in children, amitriptyline is not recommended for depressed patients under 12years of age.
Amitriptyline should be used with caution in patients with a history of seizures, impaired liver function, a history of hepatic damage or blood dyscrasias and, because of its atropine-like action, in patients with a history of urinary retention, or with narrow-angle glaucoma or increased intraocular pressure. In patients with narrow-angle glaucoma, even average doses may precipitate an attack.
There has been a report of fatal dysrhythmia occurring as late as 56hours after amitriptyline overdose.
Patients with cardiovascular disorders should be watched closely. Tricyclic antidepressant drugs, including amitriptyline, particularly when given in high doses, have been reported to produce arrhythmias, sinus tachycardia, and prolongation of the conduction time.
A few instances of unexpected deaths have been reported in patients with cardiovascular disorders. Myocardial infarction and stroke have also been reported with drugs of this class. Therefore, these drugs should be used with caution in patients with a history of cardiovascular disease, such as myocardial infarction and congestive heart failure.
Concurrent administration of amitriptyline and electroshock therapy may increase the hazards of therapy. Such treatment should be limited to patients for whom it is essential.
Close supervision is required when amitriptyline is given to hyperthyroid patients or those receiving thyroid medication.
Occupational Hazards: The drug may impair mental and/or physical abilities required for performance of hazardous tasks, such as operating machinery or driving a motor vehicle.
Pregnancy: There are no well-controlled studies in pregnant women; therefore, in administering the drug to pregnant patients or women who may become pregnant, the potential benefits must be weighed against the possible hazards to mother and child.
Lactation: Amitriptyline is detectable in breast milk. Because of the potential for serious adverse reactions in infants from amitriptyline, a decision should be made whether to discontinue nursing or discontinue the drug.
Children: In view of the lack of experience with the use of this drug in the treatment of depression in children, amitriptyline is not recommended for depressed patients under 12years of age.
Precautions
The potency of amitriptyline is such that addition of other antidepressant drugs generally does not result in any additional therapeutic benefit. Untoward reactions have been reported after the combined use of antidepressant agents having varying modes of activity. Accordingly, combined use of amitriptyline and other antidepressant drugs should be undertaken only with due recognition of the possibility of potentiation and with a thorough knowledge of the pharmacology of both drugs. There has been no reports of untoward events when patients receiving amitriptyline were changed immediately to protriptyline or vice versa.
When amitriptyline is used to treat the depressive component of schizophrenia, activation or aggravation of existing psychotic manifestations may occur. Likewise, manic depressive patients may experience hypomanic or manic episodes and hyperactive or agitated patients may become overstimulated. Paranoid delusions, with or without associated hostility, may be exaggerated. A reduction in dose or discontinuation of amitriptyline may be indicated and administration of a neuroleptic such as a phenothiazine, be considered under these circumstances.
Seriously depressed patients should be carefully supervised. The possibility of suicide in depressed patients remains during treatment. Patients should not have access to large quantities of this drug during treatment.
Discontinue the drug several days before elective surgery if possible.
Drug Interactions : Guanethidine: Amitriptyline may block the antihypertensive action of guanethidine or similarly acting compounds.
Anticholinergic Agents/Sympathomimetic Drugs: When amitriptyline is given with anticholinergic agents or sympathomimetic drugs, including epinephrine combined with local anesthetics, close supervision and careful adjustment of dosage are required. Paralytic ileus may occur in patients taking tricyclic antidepressants in combination with anticholinergic-type drugs.
Since amitriptyline, in combination with anticholinergic type drugs, may give rise to paralytic ileus, particularly in elderly or hospitalized patients, appropriate measures should be taken if constipation occurs in these patients.
Hyperpyrexia has been reported when tricyclic antidepressants are administered with anticholinergic agents or with neuroleptic drugs, particularly during hot weather.
CNS Depressants: Caution is advised if patients receive large doses of ethchlorvynol concurrently. Transient delirium has been reported in patients who were treated with 1g of ethchlorvynol and 75to 150mg of amitriptyline.
Amitriptyline may enhance the response to alcohol and the effects of barbiturates and other CNS depressants.
Disulfiram: Delirium has been reported with concurrent administration of amitriptyline and disulfiram.
Drug Metabolized by Cytochrome P450 2D6: Concomitant use of tricyclic antidepressants with drugs that can inhibit cytochrome P450 2D6 (e.g., quinidine; cimetidine) and those that are substrates for P450 2D6 (many other antidepressants, phenothiazines, and the Type 1C antiarrhythmics, propafenone and flecainide) may require lower doses than usually prescribed for either the tricyclic antidepressant or the other drug. Whenever one of these other drugs is withdrawn from cotherapy, an increased dose of tricyclic antidepressant may be required. While all the selective serotonin reuptake inhibitors (SSRIs), e.g., fluoxetine, sertraline and paroxetine, inhibit P450 2D6, they may vary in the extent of inhibition.
Serotonin Syndrome: The “serotonin syndrome” (alterations in cognition, behavior, autonomic nervous system function, and neuromuscular activity) has been reported with amitriptyline when given concomitantly with other serotonin-enhancing drugs.
The potency of amitriptyline is such that addition of other antidepressant drugs generally does not result in any additional therapeutic benefit. Untoward reactions have been reported after the combined use of antidepressant agents having varying modes of activity. Accordingly, combined use of amitriptyline and other antidepressant drugs should be undertaken only with due recognition of the possibility of potentiation and with a thorough knowledge of the pharmacology of both drugs. There has been no reports of untoward events when patients receiving amitriptyline were changed immediately to protriptyline or vice versa.
When amitriptyline is used to treat the depressive component of schizophrenia, activation or aggravation of existing psychotic manifestations may occur. Likewise, manic depressive patients may experience hypomanic or manic episodes and hyperactive or agitated patients may become overstimulated. Paranoid delusions, with or without associated hostility, may be exaggerated. A reduction in dose or discontinuation of amitriptyline may be indicated and administration of a neuroleptic such as a phenothiazine, be considered under these circumstances.
Seriously depressed patients should be carefully supervised. The possibility of suicide in depressed patients remains during treatment. Patients should not have access to large quantities of this drug during treatment.
Discontinue the drug several days before elective surgery if possible.
Drug Interactions : Guanethidine: Amitriptyline may block the antihypertensive action of guanethidine or similarly acting compounds.
Anticholinergic Agents/Sympathomimetic Drugs: When amitriptyline is given with anticholinergic agents or sympathomimetic drugs, including epinephrine combined with local anesthetics, close supervision and careful adjustment of dosage are required. Paralytic ileus may occur in patients taking tricyclic antidepressants in combination with anticholinergic-type drugs.
Since amitriptyline, in combination with anticholinergic type drugs, may give rise to paralytic ileus, particularly in elderly or hospitalized patients, appropriate measures should be taken if constipation occurs in these patients.
Hyperpyrexia has been reported when tricyclic antidepressants are administered with anticholinergic agents or with neuroleptic drugs, particularly during hot weather.
CNS Depressants: Caution is advised if patients receive large doses of ethchlorvynol concurrently. Transient delirium has been reported in patients who were treated with 1g of ethchlorvynol and 75to 150mg of amitriptyline.
Amitriptyline may enhance the response to alcohol and the effects of barbiturates and other CNS depressants.
Disulfiram: Delirium has been reported with concurrent administration of amitriptyline and disulfiram.
Drug Metabolized by Cytochrome P450 2D6: Concomitant use of tricyclic antidepressants with drugs that can inhibit cytochrome P450 2D6 (e.g., quinidine; cimetidine) and those that are substrates for P450 2D6 (many other antidepressants, phenothiazines, and the Type 1C antiarrhythmics, propafenone and flecainide) may require lower doses than usually prescribed for either the tricyclic antidepressant or the other drug. Whenever one of these other drugs is withdrawn from cotherapy, an increased dose of tricyclic antidepressant may be required. While all the selective serotonin reuptake inhibitors (SSRIs), e.g., fluoxetine, sertraline and paroxetine, inhibit P450 2D6, they may vary in the extent of inhibition.
Serotonin Syndrome: The “serotonin syndrome” (alterations in cognition, behavior, autonomic nervous system function, and neuromuscular activity) has been reported with amitriptyline when given concomitantly with other serotonin-enhancing drugs.
Side Effects / Adverse Effects
Note: Included in this listing which follows are a few adverse reactions which have not been reported with this specific drug. However, pharmacological similarities among the tricyclic antidepressant drugs require that each of the reactions be considered when amitriptyline is administered.
Behavioral: drowsiness, fatigue, activation of latent schizophrenia, disorientation, confusional states, hallucinations, delusions, hypomanic reactions, disturbed concentration, nightmares, insomnia, restlessness, agitation, excitement, jitteriness, anxiety, giddiness.
Neurological: epileptiform seizures, coma, dizziness, tremors, numbness, tingling, paresthesias of the extremities, peripheral neuropathy, headache, ataxia, alteration in EEG patterns, extrapyramidal symptoms including abnormal involuntary movements and tardive dyskinesia, dysarthria, tinnitus, incoordination, and slurred speech.
Anticholinergic: urinary retention, dilatation of the urinary tract, constipation, paralytic ileus, especially in the elderly, hyperpyrexia, dry mouth, blurred vision, disturbance of accommodation, increased intraocular pressure, precipitation of latent glaucoma, aggravation of existing glaucoma, and mydriasis.
Cardiovascular: quinidine-like effect and other non-specific ECG changes and changes in AV conduction, prolonged conduction time, asystole, hypotension, syncope, hypertension, palpitation, arrhythmias, heart block, ventricular tachycardia, fibrillation, myocardial infarction, stroke, unexpected death in patients with cardiovascular disorders.
Hematologic: bone marrow depression, including agranulocytosis, leukopenia, eosinophilia, purpura, thrombocytopenia.
Allergic: skin rash, pruritus, urticaria, photosensitization, edema of the face and tongue, itching.
Gastrointestinal: nausea, epigastric distress, heartburn, vomiting, hepatitis (including altered liver function and jaundice), anorexia, stomatitis, peculiar taste, diarrhea, parotid swelling, black tongue may occur.
Endocrine: testicular swelling, gynecomastia and impotence in the male, breast enlargement and galactorrhea in the female, increased or decreased libido, elevation and lowering of blood sugar levels, syndrome of inappropriate ADH (antidiuretic hormone) secretion.
Miscellaneous: weakness, increased perspiration, edema, urinary frequency, alopecia, increased appetite, weight gain, weight loss.
Withdrawal Symptoms: Abrupt cessation of treatment after prolonged administration may produce nausea, headache, and malaise. Gradual dosage reduction has been reported to produce, within 2weeks, transient symptoms including irritability, restlessness, and dream and sleep disturbance. These symptoms are not indicative of addiction. Rare instances have been reported of mania or hypomania occurring within 2to 7days following cessation of chronic therapy with tricyclic antidepressants.
Note: Included in this listing which follows are a few adverse reactions which have not been reported with this specific drug. However, pharmacological similarities among the tricyclic antidepressant drugs require that each of the reactions be considered when amitriptyline is administered.
Behavioral: drowsiness, fatigue, activation of latent schizophrenia, disorientation, confusional states, hallucinations, delusions, hypomanic reactions, disturbed concentration, nightmares, insomnia, restlessness, agitation, excitement, jitteriness, anxiety, giddiness.
Neurological: epileptiform seizures, coma, dizziness, tremors, numbness, tingling, paresthesias of the extremities, peripheral neuropathy, headache, ataxia, alteration in EEG patterns, extrapyramidal symptoms including abnormal involuntary movements and tardive dyskinesia, dysarthria, tinnitus, incoordination, and slurred speech.
Anticholinergic: urinary retention, dilatation of the urinary tract, constipation, paralytic ileus, especially in the elderly, hyperpyrexia, dry mouth, blurred vision, disturbance of accommodation, increased intraocular pressure, precipitation of latent glaucoma, aggravation of existing glaucoma, and mydriasis.
Cardiovascular: quinidine-like effect and other non-specific ECG changes and changes in AV conduction, prolonged conduction time, asystole, hypotension, syncope, hypertension, palpitation, arrhythmias, heart block, ventricular tachycardia, fibrillation, myocardial infarction, stroke, unexpected death in patients with cardiovascular disorders.
Hematologic: bone marrow depression, including agranulocytosis, leukopenia, eosinophilia, purpura, thrombocytopenia.
Allergic: skin rash, pruritus, urticaria, photosensitization, edema of the face and tongue, itching.
Gastrointestinal: nausea, epigastric distress, heartburn, vomiting, hepatitis (including altered liver function and jaundice), anorexia, stomatitis, peculiar taste, diarrhea, parotid swelling, black tongue may occur.
Endocrine: testicular swelling, gynecomastia and impotence in the male, breast enlargement and galactorrhea in the female, increased or decreased libido, elevation and lowering of blood sugar levels, syndrome of inappropriate ADH (antidiuretic hormone) secretion.
Miscellaneous: weakness, increased perspiration, edema, urinary frequency, alopecia, increased appetite, weight gain, weight loss.
Withdrawal Symptoms: Abrupt cessation of treatment after prolonged administration may produce nausea, headache, and malaise. Gradual dosage reduction has been reported to produce, within 2weeks, transient symptoms including irritability, restlessness, and dream and sleep disturbance. These symptoms are not indicative of addiction. Rare instances have been reported of mania or hypomania occurring within 2to 7days following cessation of chronic therapy with tricyclic antidepressants.
Overdose
Deaths may occur from overdosage with this class of drugs. Multiple drug ingestion (including alcohol) is common in deliberate tricyclic antidepressant overdose. As management of overdose is complex and changing, it is recommended that the physician contact a Poison Control Centre for current information on treatment. Signs and symptoms of toxicity develop rapidly after tricyclic antidepressant overdose, therefore, hospital monitoring is required as soon as possible.
Symptoms:
Critical manifestations of overdosage include: cardiac dysrhythmias, severe hypotension, convulsions, and CNS depression, including coma. Changes in the ECG, particularly in QRS axis or width, are clinically significant indicators of tricyclic antidepressant toxicity.
Other signs of overdose may include: confusion, disturbed concentration, transient visual hallucinations, dilated pupils, agitation, hyperactive reflexes, stupor, drowsiness, muscle rigidity, vomiting, hypothermia, hyperpyrexia, or any of the symptoms listed under Adverse Effects.
Treatment: General: Obtain an ECG and immediately initiate cardiac monitoring. Protect the patient's airway, establish an i.v. line and initiate gastric decontamination. A minimum of 6 hours of observation with cardiac monitoring and observation for signs of CNS or respiratory depression, hypotension, cardiac dysrhythmias and/or conduction blocks, and seizures is necessary. If signs of toxicity occur at any time during this period, extended monitoring is required. There are case reports of patients succumbing to fatal dysrhythmias late after overdose. These patients had clinical evidence of significant poisoning prior to death and most received inadequate gastrointestinal decontamination. Monitoring of plasma drug levels should not guide management of the patient.
Gastrointestinal Decontamination: All patients suspected of a tricyclic antidepressant overdose should receive gastrointestinal decontamination. This should include large volume gastric lavage followed by activated charcoal. If consciousness is impaired, the airway should be secured prior to lavage. Emesis is contraindicated.
Cardiovascular: A maximal limb-lead QRS duration of ³0.10 seconds may be the best indication of the severity of the overdose. I.V. sodium bicarbonate should be used to maintain the serum pH in the range of 7.45 to 7.55. If the pH response is inadequate, hyperventilation may also be used. Concomitant use of hyperventilation and sodium bicarbonate should be done with extreme caution, with frequent pH monitoring. A pH >7.60 or a pCO 2 <20 mmHg is undesirable. Dysrhythmias unresponsive to sodium bicarbonate therapy/hyperventilation may respond to lidocaine, bretylium or phenytoin. Type 1A and 1C antiarrhythmics are generally contraindicated (e.g., quinidine, disopyramide, and procainamide).
In rare instances, hemoperfusion may be beneficial in acute refractory cardiovascular instability in patients with acute toxicity. However, hemodialysis, peritoneal dialysis, exchange transfusions, and forced diuresis generally have been reported as ineffective in tricyclic antidepressant poisoning.
CNS: In patients with CNS depression, early intubation is advised because of the potential for abrupt deterioration. Seizures should be controlled with benzodiazepines or, if these are ineffective, other anticonvulsants (e.g., phenobarbital, phenytoin). Physostigmine is not recommended except to treat life-threatening symptoms that have been unresponsive to other therapies, and then only in close consultation with a Poison Control Centre.
Psychiatric Follow-up: Since overdosage is often deliberate, patients may attempt suicide by other means during the recovery phase. Psychiatric referral may be appropriate.
Pediatric Management: The principles of management of child and adult overdosages are similar. It is strongly recommended that the physician contact the local Poison Control Centre for specific pediatric treatment.
Deaths may occur from overdosage with this class of drugs. Multiple drug ingestion (including alcohol) is common in deliberate tricyclic antidepressant overdose. As management of overdose is complex and changing, it is recommended that the physician contact a Poison Control Centre for current information on treatment. Signs and symptoms of toxicity develop rapidly after tricyclic antidepressant overdose, therefore, hospital monitoring is required as soon as possible.
Symptoms:
Critical manifestations of overdosage include: cardiac dysrhythmias, severe hypotension, convulsions, and CNS depression, including coma. Changes in the ECG, particularly in QRS axis or width, are clinically significant indicators of tricyclic antidepressant toxicity.
Other signs of overdose may include: confusion, disturbed concentration, transient visual hallucinations, dilated pupils, agitation, hyperactive reflexes, stupor, drowsiness, muscle rigidity, vomiting, hypothermia, hyperpyrexia, or any of the symptoms listed under Adverse Effects.
Treatment: General: Obtain an ECG and immediately initiate cardiac monitoring. Protect the patient's airway, establish an i.v. line and initiate gastric decontamination. A minimum of 6 hours of observation with cardiac monitoring and observation for signs of CNS or respiratory depression, hypotension, cardiac dysrhythmias and/or conduction blocks, and seizures is necessary. If signs of toxicity occur at any time during this period, extended monitoring is required. There are case reports of patients succumbing to fatal dysrhythmias late after overdose. These patients had clinical evidence of significant poisoning prior to death and most received inadequate gastrointestinal decontamination. Monitoring of plasma drug levels should not guide management of the patient.
Gastrointestinal Decontamination: All patients suspected of a tricyclic antidepressant overdose should receive gastrointestinal decontamination. This should include large volume gastric lavage followed by activated charcoal. If consciousness is impaired, the airway should be secured prior to lavage. Emesis is contraindicated.
Cardiovascular: A maximal limb-lead QRS duration of ³0.10 seconds may be the best indication of the severity of the overdose. I.V. sodium bicarbonate should be used to maintain the serum pH in the range of 7.45 to 7.55. If the pH response is inadequate, hyperventilation may also be used. Concomitant use of hyperventilation and sodium bicarbonate should be done with extreme caution, with frequent pH monitoring. A pH >7.60 or a pCO 2 <20 mmHg is undesirable. Dysrhythmias unresponsive to sodium bicarbonate therapy/hyperventilation may respond to lidocaine, bretylium or phenytoin. Type 1A and 1C antiarrhythmics are generally contraindicated (e.g., quinidine, disopyramide, and procainamide).
In rare instances, hemoperfusion may be beneficial in acute refractory cardiovascular instability in patients with acute toxicity. However, hemodialysis, peritoneal dialysis, exchange transfusions, and forced diuresis generally have been reported as ineffective in tricyclic antidepressant poisoning.
CNS: In patients with CNS depression, early intubation is advised because of the potential for abrupt deterioration. Seizures should be controlled with benzodiazepines or, if these are ineffective, other anticonvulsants (e.g., phenobarbital, phenytoin). Physostigmine is not recommended except to treat life-threatening symptoms that have been unresponsive to other therapies, and then only in close consultation with a Poison Control Centre.
Psychiatric Follow-up: Since overdosage is often deliberate, patients may attempt suicide by other means during the recovery phase. Psychiatric referral may be appropriate.
Pediatric Management: The principles of management of child and adult overdosages are similar. It is strongly recommended that the physician contact the local Poison Control Centre for specific pediatric treatment.
Recommended Dosage
Dosage should be initiated at a low level and increased gradually, noting carefully the clinical response and any evidence of intolerance.
Outpatient Adults: The recommended initial dose for ambulatory patients is 25mg 3times a day. Depending upon tolerance and response, this may be increased to a total of 150mg a day. Increases are made preferably in the late afternoon and/or bedtime doses. The sedative effect is usually rapidly apparent. The antidepressant activity may be evident within 3or 4days or may take up to 30days to develop adequately.
Hospitalized Patients: Severely ill or hospitalized patients may require 100mg a day initially. This can be increased gradually to 200mg a day if necessary. A small number of hospitalized patients may need as much as 300mg a day.
Adolescent and Elderly Patients: In general, lower dosages are recommended for these patients. In those patients who may not tolerate higher doses, 50mg daily may be satisfactory. The dose may be administered in divided doses or as a single dose preferably in the evening or at bedtime.
Maintenance: When satisfactory improvement has been reached, dosage should be reduced to the lowest amount that will maintain relief of symptoms. The usual maintenance dose is 50to 100mg/day in divided doses; however, in suitable patients, the total daily dosage may be given in a single dose, preferably at bedtime. It is appropriate to continue maintenance therapy throughout the active phase of the depression and for the expected duration of the depressive episode, in order to lessen the possibility of relapse.
Plasma Levels: Because of the wide variation in the absorption and distribution of tricyclic antidepressants in body fluids, it is difficult to directly correlate plasma levels and therapeutic effect. However, determination of plasma levels may be useful in identifying patients who appear to have toxic effects and may have excessively high levels, or those in whom lack of absorption or non-compliance is suspected. Adjustments in dosage should be made according to the patient's clinical response and not on the basis of plasma levels.
Dosage should be initiated at a low level and increased gradually, noting carefully the clinical response and any evidence of intolerance.
Outpatient Adults: The recommended initial dose for ambulatory patients is 25mg 3times a day. Depending upon tolerance and response, this may be increased to a total of 150mg a day. Increases are made preferably in the late afternoon and/or bedtime doses. The sedative effect is usually rapidly apparent. The antidepressant activity may be evident within 3or 4days or may take up to 30days to develop adequately.
Hospitalized Patients: Severely ill or hospitalized patients may require 100mg a day initially. This can be increased gradually to 200mg a day if necessary. A small number of hospitalized patients may need as much as 300mg a day.
Adolescent and Elderly Patients: In general, lower dosages are recommended for these patients. In those patients who may not tolerate higher doses, 50mg daily may be satisfactory. The dose may be administered in divided doses or as a single dose preferably in the evening or at bedtime.
Maintenance: When satisfactory improvement has been reached, dosage should be reduced to the lowest amount that will maintain relief of symptoms. The usual maintenance dose is 50to 100mg/day in divided doses; however, in suitable patients, the total daily dosage may be given in a single dose, preferably at bedtime. It is appropriate to continue maintenance therapy throughout the active phase of the depression and for the expected duration of the depressive episode, in order to lessen the possibility of relapse.
Plasma Levels: Because of the wide variation in the absorption and distribution of tricyclic antidepressants in body fluids, it is difficult to directly correlate plasma levels and therapeutic effect. However, determination of plasma levels may be useful in identifying patients who appear to have toxic effects and may have excessively high levels, or those in whom lack of absorption or non-compliance is suspected. Adjustments in dosage should be made according to the patient's clinical response and not on the basis of plasma levels.
Supplied / Packaging
10 mg: Each blue, biconvex, discoid-shaped, film-coated tablet, 0.63 cm in diameter, engraved MSD23 on one side, contains: amitriptyline HCl 10mg. Nonmedicinal ingredients: brilliant blue (sodium and sodium alumina), calcium phosphate dibasic dihydrate, carnauba wax, colloidal silicon dioxide, cornstarch, hydroxypropyl cellulose, hydroxypropyl methylcellulose, lactose, magnesium stearate, powdered cellulose, stearic acid, talc and titanium dioxide. Bottles of 100.
25 mg: Each yellow, biconvex, discoid-shaped, film-coated tablet, 0.63cm in diameter, engraved MSD45 on one side, contains: amitriptyline HCl 25mg. Nonmedicinal ingredients: brilliant blue sodium alumina, calcium phosphate dibasic dihydrate, carnauba wax, colloidal silicon dioxide, cornstarch, hydroxypropyl cellulose, hydroxypropyl methylcellulose, lactose, magnesium stearate, powdered cellulose, quinoline yellow, stearic acid, sunset yellow, talc and titanium dioxide. Bottles of 100.
50 mg: Each beige, biconvex, discoid-shaped, film-coated tablet, 0.79cm in diameter, engraved MSD102 on one side, contains: amitriptyline HCl 50mg. Nonmedicinal ingredients: calcium phosphate dibasic dihydrate, carnauba wax, colloidal silicon dioxide, cornstarch, hydroxypropyl cellulose, hydroxypropyl methylcellulose, lactose, magnesium stearate, powdered cellulose, quinoline yellow, red and black iron oxides, stearic acid, sunset yellow, talc and titanium dioxide. Bottles of 100.
75 mg: Each orange, biconvex, discoid-shaped, film-coated tablet, 1.03cm in diameter, engraved MSD430 on one side, contains: amitriptyline HCl 75mg. Nonmedicinal ingredients: calcium phosphate dibasic dihydrate, carnauba wax, colloidal silicon dioxide, cornstarch, hydroxypropyl cellulose, hydroxypropyl methylcellulose, lactose, magnesium stearate, powdered cellulose, stearic acid, sunset yellow alumina, talc and titanium dioxide. Bottles of 100.
10 mg: Each blue, biconvex, discoid-shaped, film-coated tablet, 0.63 cm in diameter, engraved MSD23 on one side, contains: amitriptyline HCl 10mg. Nonmedicinal ingredients: brilliant blue (sodium and sodium alumina), calcium phosphate dibasic dihydrate, carnauba wax, colloidal silicon dioxide, cornstarch, hydroxypropyl cellulose, hydroxypropyl methylcellulose, lactose, magnesium stearate, powdered cellulose, stearic acid, talc and titanium dioxide. Bottles of 100.
25 mg: Each yellow, biconvex, discoid-shaped, film-coated tablet, 0.63cm in diameter, engraved MSD45 on one side, contains: amitriptyline HCl 25mg. Nonmedicinal ingredients: brilliant blue sodium alumina, calcium phosphate dibasic dihydrate, carnauba wax, colloidal silicon dioxide, cornstarch, hydroxypropyl cellulose, hydroxypropyl methylcellulose, lactose, magnesium stearate, powdered cellulose, quinoline yellow, stearic acid, sunset yellow, talc and titanium dioxide. Bottles of 100.
50 mg: Each beige, biconvex, discoid-shaped, film-coated tablet, 0.79cm in diameter, engraved MSD102 on one side, contains: amitriptyline HCl 50mg. Nonmedicinal ingredients: calcium phosphate dibasic dihydrate, carnauba wax, colloidal silicon dioxide, cornstarch, hydroxypropyl cellulose, hydroxypropyl methylcellulose, lactose, magnesium stearate, powdered cellulose, quinoline yellow, red and black iron oxides, stearic acid, sunset yellow, talc and titanium dioxide. Bottles of 100.
75 mg: Each orange, biconvex, discoid-shaped, film-coated tablet, 1.03cm in diameter, engraved MSD430 on one side, contains: amitriptyline HCl 75mg. Nonmedicinal ingredients: calcium phosphate dibasic dihydrate, carnauba wax, colloidal silicon dioxide, cornstarch, hydroxypropyl cellulose, hydroxypropyl methylcellulose, lactose, magnesium stearate, powdered cellulose, stearic acid, sunset yellow alumina, talc and titanium dioxide. Bottles of 100.
