Buy Generic Pamelor
(Generic name: Nortriptyline)
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Buy Generic Pamelor from a Discount International Pharmacy.
(Generic name: Nortriptyline)
Antidepressant
The mechanism of mood elevation of tricyclic antidepressants is at present
unknown. Nortriptyline is not an MAO inhibitor. It inhibits the activity of such
diverse agents as histamine, 5-hydroxytryptamine, and acetylcholine. It
increases the pressor effect of norepinephrine but blocks the pressor response
of phenethylamine. Studies suggest that nortriptyline interferes with the
transport, release, and storage of catecholamines.
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The relief of symptoms of depression. Endogenous depressions are more likely
to be alleviated than are other depressive states.
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The concurrent use of nortriptyline or other tricyclic antidepressants with a
MAO inhibitor is contraindicated. Hyperpyretic crises, severe convulsions, and
fatalities have occurred when similar tricyclic antidepressants were used in
such combinations. Discontinue the MAO inhibitor at least 2 weeks before
nortriptyline treatment is started. Patients hypersensitive to nortriptyline
should not be given the drug.
Cross sensitivity between nortriptyline and other dibenzazepines is a
possibility.
Nortriptyline is contraindicated during the acute recovery period after
myocardial infarction.
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Patients with cardiovascular disease should be given nortriptyline only under
close supervision because of the tendency of the drug to produce sinus
tachycardia and to prolong the conduction time. Myocardial infarction,
arrhythmia, and strokes have occurred. The antihypertensive action of
guanethidine and similar agents may be blocked. Because of its anticholinergic
activity, use nortriptyline with great caution in patients with glaucoma or a
history of urinary retention. Patients with a history of seizures should be
followed closely when nortriptyline is administered because this drug is known
to lower the convulsive threshold. Great care is required if nortriptyline is
administered to hyperthyroid patients or those receiving thyroid medication,
because cardiac arrhythmias may develop.
Occupational Hazards:
Nortriptyline may impair the mental and/or physical abilities required for the
performance of hazardous tasks, such as operating machinery or driving a car;
therefore, warn the patient accordingly.
Pregnancy and Lactation:
Safe use of nortriptyline during pregnancy and lactation has not been
established; therefore, when the drug is administered to pregnant patients,
nursing mothers, or women of childbearing age, the potential benefits must be
weighed against the possible hazards. Animal reproduction studies have yielded
inconclusive results.
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The use of nortriptyline in schizophrenic patients may result in an
exacerbation of the psychosis or may activate latent schizophrenic symptoms. If
the drug is given to overactive or agitated patients, increased anxiety and
agitation may occur. In manic depressive patients, nortriptyline may cause
symptoms of the manic phase to emerge.
Troublesome patient hostility may be aroused by the use of nortriptyline.
Epileptiform seizures may accompany its administration, as may happen with other
drugs of its class.
Close supervision and careful adjustment of the dosage are required when
nortriptyline is used with other anticholinergic drugs and sympathomimetic
drugs.
Inform the patient that the response to alcohol may be exaggerated. Excessive
consumption of alcohol in combination with nortriptyline therapy may have a
potentiating effect, which may lead to the danger of increased suicidal attempts
or overdosage, especially in patients with histories of emotional disturbances
or suicidal ideation.
When it is essential, the drug may be administered concurrently with
electroconvulsive therapy, although the hazards may be increased. Discontinue
the drug for several days, if possible, prior to elective surgery.
The possibility of a suicidal attempt by depressed patients remains after the
initiation of treatment; in this regard, it is important that the least possible
quantity of drug be dispensed at any given time.
Both elevation and lowering of blood sugar levels have been reported. A case
of significant hypoglycemia has been reported in a Type II diabetic patient
maintained on chlorpropamide (250 mg/day) after the addition of nortriptyline
(125 mg/day).
Drug Interactions:
Steady state serum concentrations of the tricyclic antidepressants are reported
to fluctuate significantly as cimetidine is either added or deleted from the
drug regimen. Serious anticholinergic symptoms (severe dry mouth, urinary
retention, blurred vision) have been associated with elevations in the serum
levels of the tricyclic antidepressant when cimetidine is added to the drug
regimen. In addition, higher than expected steady state serum concentrations of
the tricyclic antidepressant have been observed when therapy is initiated in
patients already taking cimetidine.
In well-controlled patients undergoing concurrent therapy with cimetidine, a
decrease in the steady state serum concentrations of the tricyclic
antidepressants may occur when cimetidine therapy is discontinued. The
therapeutic efficacy of the tricyclic antidepressant may be compromised in these
patients as the cimetidine is discontinued. Several of the tricyclic
antidepressants have been cited in these reports.
There have been greater than two-fold increases in previously stable plasma
levels of other antidepressants including nortriptyline, when fluoxetine has
been administered in combination with these agents. Fluoxetine and its active
metabolite, norfluoxetine, have a long half-life (7 to 9 days for norfluoxetine)
which might affect strategies during conversion from one drug to another.
Administration of reserpine during therapy with a tricyclic antidepressant
has been shown to produce a stimulating effect in some depressed patients.
Close supervision and careful adjustment of the dosage are required when
nortriptyline is used with other anticholinergic drugs or sympathomimetic drugs.
The patient should be informed that the response to alcohol may be
exaggerated.
Drugs Metabolized by P450IID6:
A subset (3 to 10%) of the population has reduced activity of certain drug
metabolizing enzymes such as the cytochrome P450 isoenzyme P450IID6. Such
individuals are referred to as "poor metabolizers" of drugs such as debrisoquin,
dextromethorphan, and the tricyclic antidepressants. These individuals may have
higher than expected plasma concentrations of tricyclic antidepressants when
given usual doses. In addition, certain drugs that are metabolized by this
isoenzyme, including many antidepressants (tricyclic antidepressants, selective
serotonin reuptake inhibitors, and others), may inhibit the activity of this
isoenzyme, and thus may make normal metabolizers resemble poor metabolizers with
regard to concomitant therapy with other drugs metabolized by this enzyme
system, leading to drug interactions.
Concomitant use of tricyclic antidepressants with other drugs metabolized by
cytochrome P450IID6 may require lower doses than usually prescribed for either
the tricyclic antidepressant or the other drug. Therefore, co-administration of
tricyclic antidepressants with other drugs that are metabolized by this
isoenzyme, including other antidepressants, phenothiazines, carbamazepine, and
Type 1C antiarrhythmics (e.g., propafenone, flecainide, and encainide), or that
inhibit this enzyme (e.g., quinidine), should be approached with caution.
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Note:
Included in the following list are a few adverse reactions that have not been
reported with this specific drug. However, the pharmacologic similarities among
the tricyclic antidepressant drugs require that each of these reactions be
considered when nortriptyline is administered.
Cardiovascular:
Hypotension, hypertension, tachycardia, palpitation, myocardial infarction,
arrhythmias, heart block, stroke.
Psychiatric:
Confusional states (especially in the elderly) with hallucinations,
disorientation, delusions; anxiety, restlessness, agitation; insomnia, panic,
nightmares; hypomania; exacerbation of psychosis.
Neurologic:
Numbness, tingling, paresthesias of extremities; incoordination, ataxia,
tremors; peripheral neuropathy, extrapyramidal symptoms; seizures, alteration of
EEG patterns; tinnitus.
Anticholinergic:
Dry mouth and, rarely, associated sublingual adenitis or gingivitis; blurred
vision, disturbance of accommodation, mydriasis; constipation, paralytic ileus;
urinary retention, delayed micturition, dilation of the urinary tract.
Allergic:
Skin rash, petechiae, urticaria, itching, photosensitization (avoid excessive
exposure to sunlight); edema (general or of face and tongue), drug fever,
cross-sensitivity with other tricyclic drugs.
Hematologic:
Bone-marrow depression, including agranulocytosis, aplastic anemia; eosinophilia;
purpura; thrombocytopenia.
Gastrointestinal:
Nausea and vomiting, anorexia, epigastric distress, diarrhea; peculiar taste,
stomatitis, abdominal cramps, black tongue, constipation, paralytic ileus.
Endocrine; gynecomastia in the male; breast enlargement and galactorrhea in
the female; increased or decreased libido, impotence; testicular swelling;
elevation or depression of blood sugar levels; syndrome of inappropriate ADH (antidiuretic
hormone) secretion.
Other:
Jaundice (simulating obstructive); altered liver function, hepatitis, and liver
necrosis; weight gain or loss; perspiration; flushing; urinary frequency,
nocturia; drowsiness, dizziness, weakness, fatigue; headache; parotid swelling;
alopecia.
Withdrawal Symptoms:
Though these are not indicative of addiction, abrupt cessation of treatment
after prolonged therapy may produce nausea, headache, and malaise.
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Symptoms:
Overdose of tricyclic antidepressants may be manifest with doses as small as 50
mg in a child. Of patients who are alive at initial presentation, a mortality
rate of between 0% and 15% has been reported. Symptoms of overdose of tricyclic
antidepressants may begin within several hours of oral ingestion. Symptoms and
signs may include blurred vision, confusion, restlessness, dizziness,
hypothermia, hyperthermia, agitation, vomiting, hyperactive reflexes, dilated
pupils, fever, rapid heart rate, decreased bowel sounds, dry mouth, inability to
void, myoclonic jerks, seizures, respiratory depression, myoglobinuric renal
failure, nystagmus, ataxia, dysarthria, choreoathetosis, coma, hypotension, and
cardiac arrhythmias. An effect on cardiac conduction similar to that of
quinidine may be seen with slowing of conduction, prolongation of the QRS
complex and QT intervals, right bundle branch and AV block, ventricular
tachyarrhythmias (including Torsade de pointes and fibrillation), and death.
Prolongation of the QRS duration to more than 0.1 seconds is predictive of more
severe toxicity. The absence of sinus tachycardia does not ensure a benign
course. Hypotension may be caused by vasodilation, central and peripheral
alpha-adrenergic blockade, and cardiac depression. In a healthy young person,
prolonged resuscitation may be effective; one patient was reported to survive 5
hours of cardiac massage.
Treatment:
In managing overdose, consider the possibility of multiple drug overdose,
interactions among drugs, and unusual drug kinetics in your patients. Protect
the patient's airway and support ventilation and perfusion. Meticulously monitor
and maintain, within acceptable limits, the patient's vital signs, blood gases,
serum electrolytes, etc. Absorption of drugs from the gastrointestinal tract may
be decreased by giving activated charcoal, which, in many cases, is more
effective than emesis or lavage; consider charcoal instead of or in addition to
gastric emptying. Repeated doses of charcoal over time may hasten elimination of
some drugs that have been absorbed. Safeguard the patient's airway when
employing gastric emptying or charcoal.
Ventricular arrhythmias, especially when accompanied by lengthened QRS
intervals, may respond to alkalinization by hyperventilation or administration
of sodium bicarbonate. It is important to monitor and manage serum electrolyte
levels. Refractory arrhythmias may respond to propranolol, bretyllium, or
lidocaine. Quinidine and procainamide usually should not be used because they
may exacerbate arrhythmias and conduction already slowed by the overdosage.
Seizures may respond to diazepam. Phenytoin has pharmacologic properties that
may be helpful in dealing with both the seizures and cardiac rhythm disturbances
of tricyclic antidepressant overdose. Although the prophylactic use of phenytoin
has been suggested, it is not yet of proven value.
In some patients, physostigmine may antagonize such effects of tricyclic
antidepressant overdose as atrial tachycardia, gut immotility, myoclonic jerks,
and somnolence. It is less effective for seizures and ventricular arrhythmias.
When giving physostigmine, the patient's condition should be carefully monitored
and ventilation and cardiac rhythm should be supported. Cholinergic toxicity
from physostigmine may include bronchospasm, bronchorrhea, bradycardia, asystole,
diaphoresis, incontinence, and seizures. If physostigmine is used, give it
slowly because rapid injection may cause seizures. The effects of physostigmine
may be short-lived; repeated doses may lead to continued improvement.
Diuresis and dialysis remove little of the tricyclic antidepressant present
in the body of a patient who has taken an overdose. Hemoperfusion is of unproven
benefit. The patient who has taken a tricyclic overdose should be monitored
closely, at least until the QRS duration is normal.
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Nortriptyline is not recommended for children. Nortriptyline is administered
orally in the form of capsules. Lower than usual dosages are recommended for
elderly patients and adolescents. The use of lower dosages for outpatients is
more important than for hospitalized patients who will be treated under close
supervision. The physician should initiate dosages at a low level and increase
it gradually, checking the clinical response carefully and noting any evidence
of intolerance. Following remission, maintenance medication may be required for
a long period of time at the lowest dose that will maintain remission. If a
patient develops minor side effects, the dosage should be reduced. The drug
should be discontinued promptly if adverse effects of a serious nature or
allergic manifestations occur.
Adults:
25 mg 3 or 4 times daily; dosage should begin at a low level and be increased as
required. Doses above 100 mg/day are not recommended.
Geriatrics and Adolescent Patients:
30 to 50 mg/day, in divided doses.
Plasma Levels:
Optimal responses to nortriptyline have been associated with plasma
concentrations of 50 to 150 ng/mL. Higher concentrations may be associated with
more adverse experiences. Plasma concentrations are difficult to measure, and
physicians should consult with the laboratory professional staff. Larger plasma
concentrations of the active nortriptyline metabolite 10-hydroxynortriptyline
have been reported in older patients. In one case, such a condition was
associated with apparent cardiotoxicity despite the fact that nortriptyline
concentrations were within the therapeutic range. Clinical findings should
predominate over plasma concentrations as primary determinants of dosage
changes.
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