What is imipramine, and how does it work (mechanism of action)?
Imipramine is an antidepressant medication
of the tricyclic class. Medications in this class are often referred to as
tricyclic antidepressants or TCAs. Depression is defined as an all-pervasive
sense of sadness and gloom. In patients with depression, abnormal levels of
chemicals in the brain (called neurotransmitters) may be the cause of their
depression. These neurotransmitters are chemicals that the nerves in the brain
use to communicate with each other. Imipramine is believed to elevate mood by
raising the levels of neurotransmitters in the brain. Imipramine was first
synthesized in the late 1940s and was approved by the FDA for depression in 1959
and for enuresis in 1973. PRESCRIPTION: Yes
What brand names are available for imipramine?
Tofranil, Tofranil-PM
Is imipramine available as a generic drug?
Yes
What are the side effects of imipramine?
The most common side effects of imipramine are:
- nausea,
- vomiting,
- weakness,
- confusion,
- anxiety,
- insomnia,
- increased heart rate,
- heart palpitations,
- blurred vision,
- difficulty urinating,
- dry mouth,
- constipation,
- weight gain or loss,
- rash,
- hives, and
- impotence.
Other important side effects include:
- high blood pressure,
- low blood pressure when standing (orthostatic hypotension),
- fainting,
- heart attack,
- stroke,
- seizures,
- hepatitis, and
- abnormal heart beats
- (arrhythmia).
Imipramine also can cause elevated pressure in the eyes of some
patients with glaucoma.
Following prolonged therapy with high doses, abrupt
discontinuation of TCAs, including imipramine, could lead to withdrawal symptoms
such as nausea, vomiting, diarrhea, or restlessness. Therefore, many experts
recommend gradually reducing the dose of drug if the drug is to be discontinued.
Antidepressants increased the risk of
suicidal thinking and behavior in
short-term studies in children and adolescents with depression and other
psychiatric disorders. Anyone considering the use of imipramine or any other
antidepressant in a child or adolescent must balance this risk with the clinical
need. Patients who are started on therapy should be closely observed for
clinical worsening, suicidal thinking or behavior, and unusual changes in
behavior.
What is the dosage for imipramine?
The dose range for treating
depression is 75 to 300 mg daily. It may be given as a single dose or in divided
doses. The recommended dose for enuresis is 10 to 75 mg daily at bedtime.
Which drugs or supplements interact with imipramine?
Other medications and drugs that slow the brain's
processes, such as alcohol, barbiturates, benzodiazepines, for example,
lorazepam (Ativan), diazepam (Valium), temazepam (Restoril), oxazepam (Serax),
clonazepam (Klonopin), zolpidem (Ambien), and narcotics, may add to the effect
of imipramine on the brain.
Reserpine, given to patients taking TCAs, can cause
agitation and anxiety. Imipramine and other TCAs should not be used with
monoamine oxidase inhibiting drugs, for example, isocarboxazid (Marplan),
phenelzine (Nardil), tranylcypromine (Parnate), and procarbazine (Matulane),
since high fever, convulsions and even death can occur.
Concurrent use of
cimetidine (Tagamet) can increase imipramine blood levels by reducing
elimination of imipramine from the body and possibly lead to imipramine- related
side effects. Other drugs which share this effect include propafenone (Rythmol),
flecainide (Tonocard), quinidine (Quinidex, Quinaglute), methylphenidate
(Ritalin), and fluoxetine (Prozac).
Is imipramine safe to take if I’m pregnant or breastfeeding?
Use of imipramine during
pregnancy has not been adequately
evaluated.
Available evidence suggests that imipramine may be
excreted in
breast milk and may be harmful to the infant.
What else should I know about imipramine?
What preparations of imipramine are available?
Tablets: 10, 25 and 50 mg. Capsule: 75, 100, 125 and 150
mg.
How should I keep imipramine stored?
Imipramine should be stored below 86 F (30 C) in a tight,
light resistant container.