Overview
Trilafon is the brand name for perphenazine, a medium potency antipsychotic medication in a class of drugs called phenothiazines. Antipsychotics work by blocking the neurotransmitter dopamine in the brain.

The effects of Trilafon may be felt after 3 to 6 weeks, though it may take longer for full effectiveness.

Note: Some drugs contain both perphenazine and amitriptyline, an antidepressant. These medications are used to treat slightly different symptoms than medications that contain perphenazine only. The drug information for both medications must be considered when taking these combination drugs. Drugs that contain this combination include: Etrafon, Triavil, and PMS-Levazine.

Why is this drug prescribed?
Trilafon is used to treat:

1. schizophrenia
2. severe nausea and vomiting
   

Warnings
Trilafon may cause dizziness or loss of alertness. Patients should not drive or operate heavy machinery until it is known that Trilafon does not interfere with the ability to safely engage in such activities.

Trilafon is associated with an increased risk of heat stroke; patients should avoid extreme heat.

Suddenly discontinuing Trilafon may cause severe withdrawal symptoms. Dosage should be gradually tapered when Trilafon is discontinued.

When Trilafon is taken for a long time, patients are advised to take a riboflavin (vitamin B2) supplement.

For Pregnant or Nursing Mothers: Trilafon's effects during pregnancy and breast-feeding are not well studied. Trilafon is not recommended for pregnant or nursing women.

Contraindications
Trilafon should Not be used for people with the following medical conditions:

1. allergy or sensitivity to Trilafon
2. central nervous system (CNS) depression or taking large doses of CNS depressants
3. bone marrow suppression
4. liver damage or disease (severe)
5. blood disease
6. subcortical damage
7. coma

Precautions
Trilafon may be used with caution in people with the following conditions:

1. glaucoma
2. epilepsy
3. Parkinson's disease
4. an enlarged prostate
5. difficulty urinating
6. liver or kidney disease

Adverse Reactions
Trilafon may cause the following reactions:

1. drowsiness
2. dry mouth
3. nasal congestion
4. constipation
5. lowering of blood pressure
6. weight gain
7. skin rash
8. headache
9. dizziness
10. blurred vision
11. insomnia
12. depression
13. rapid heartbeat
14. increased sensitivity to sunlight
15. nausea
16. jaundice (yellowing of the whites of the eyes or skin),
17. raised blood pressure
18. neuroleptic malignant syndrome (NMS)
19. tardive dyskinesia
20. involuntary movements of arms and legs
21. seizures
22. disorientation
23. heat stroke

Interactions with Drugs and Other Substances
Drugs or substances that may interact with Trilafon include:

1. MAO Inhibitors (within 14 days) — serious, even fatal, interactions can occur
2. coffee, tea, cola, grape, or apple juice (with the liquid form of Trilafon only) — the liquid form should not be mixed with any of these. Water or ginger ale, pudding or applesauce may be used, if desired
3. Ismelin (guanethidine), and oral antidiabetics — Trilafon may decrease the effects of these medications
4. atropinelike drugs — taken with Trilafon may cause drug toxicity
5. sedative drugs such as Demerol (meperidine), cough, cold, or allergy medications, sleep aids, antidepressants, seizure medication, and muscle relaxants — Trilafon can increase sedation
6. lithium — Trilafon may decrease its effects, and combination may cause drug toxicity
7. Antacids containing aluminum or magnesium (within 2 hours before or after Trilafon) — can decrease the effects of Trilafon
8. vitamin C, barbiturates, Cogentin (benztropine), Antabuse (disulfiram), and Artane (trihexyphenidyl) — can decrease Trilafon's effects
9. blood pressure medications such as propranolol (Inderal), methyldopa (Aldomet), and clonidine (Catapres) — can increase side effects such as dizziness
10. anticoagulants such as warfarin (Coumadin) — Trilafon can decrease the effects of these medications and cause blood clots
11. alcohol — can increase sedation and depression of brain function
12. marijuana — can increase drowsiness and may cause an increase in psychotic symptoms

Sources

http://www.psyweb.com/Drughtm/perphe.html

http://www.health-center.com/mentalhealth/schizophrenia/schizophrenia_/trilafon1.htm

http://onhealth.webmd.com/conditions/resource/pharmacy/multum0/item,75026.asp

http://alzheimers.about.com/health/alzheimers/library/bltrilafon.htm