Name and Chemical Formula. Protriptyline (pro-TRIP-till-eene) is a tricyclic antidepressant; sometimes patients with apnea take it as well. Its chemical formula is C₁₈H₂₂N, and it's often sold under the trade name Vivactil.

Purpose. As with most of the tricyclics, protriptyline is generally prescribed only to those patients who have not benefited from the SSRIs or the atypical antidepressants. It exerts only a mild sedative effect; patients who need a sedating antidepressant generally take amitriptyl1ne or doxepin instead.

Side-effects. Protriptyline does inhibit acetylcholine reuptake to an extent, so it can produce the typical side-effects of anticholinergic drugs (dry mouth, constipation or diarrhea, tachycardia or bradycardia, headache, nausea, insomnia, drowsiness, and anxiety).

Contraindications. Protriptyline is usually not prescribed to patients with the following conditions:

• epilepsy or other seizure disorder
• a history of heart attack or any other cardiovascular problems
• kidney or liver disorders
• bipolar disorder

Drug Interactions:

• MAO Inhibitors
• neuroleptics
• any other anticholinergic drugs, whether legal or illegal

Neil is absolutely right; you should be aware of the limitations of everything drug nodes.

Some drug interactions with protriptyline you should know about:

• Anticholinergic agents (atropine, antihistamines, antiparkinson drugs, antipsychotics, cold and allergy medications): increased anticholinergic effects.
• CNS depressants: additive depressive effects. Don't do this. Avoid alcohol, sleeping pills, etc.
• MAOIs: causes dangerously high blood pressure and possibly atropine poisoning. If you're on an MAOI, you should probably be avoiding pretty much all other antidepressants.
• Oral contraceptives inhibit the effects of tricyclic antidepressants such as protriptyline.

There are other drug interactions patients on protriptyline can be affected by. Ask your doctor or pharmacist. You shouldn't rely solely on the Interweb for medical information.

Source: Keltner and Folks, Psychotropic Drugs, 2nd ed. St. Louis: Mosby, 1997.