Psychiatric side effects associated with the ten most commonly dispensed prescription drugs: a review

Journal of Family Practice, August, 1991 by John R. Hubbard, James L. Levenson, Graham A. Patrick

In addition to the studies cited above, cimetidine (probably because of its increased effect on hepatic P-450 and P-448 MFO systems) poses potential problems with drug interactions that may be of psychiatric importance.[62,71-74] For example, the combinations of 300 mg three times per day of cimetidine with 0.375 mg of triazolam at bedtime produced both visual and auditory hallucinations in a 49-year-old woman, presumably as a result of decreased clearance of the triazolam.[74] Other reports, particularly of decreased metabolism of tricyclic antidepressants in the presence of cimetidine, indicate the need for monitoring drug levels.

Although initial studies with [H.sub.2]-receptor antagonists did not reveal significant adverse neuropsychiatric side effects,[57,58] the widespread use of these drugs has led to numerous reports of many potential psychiatric symptoms that may occur (particularly with cimetidine) in susceptible patients. Most studies were case reports, but many appeared to be substantiated by rechallenge of the drug to produce similar behavioral change(s). In light of these observations and the popular use of these agents, further study would prove helpful to clarify and quantify these potential adverse reactions.

Dyazide

GENERIC-HYDROCHLOROTHIAZIDE (25 MG) AND TRIAMTERENE (50 MG)

OTHER COMMON BRAND NAME-MAXZIDE

General Information. Hydrochlorothiazide/triamterene is commonly administered at one to two capsules per day (maximum four per day). [11] The drugs are used primarily to treat hypertension, and also for edema caused by congestive heart failure or cirrhosis of the liver. [11] Hydrochlorothiazide (HCITZ) and triamterene act as diuretics by inhibiting sodium reabsorption (and hydrogen and potassium secretion) in the cortical collecting tubule (and distal convoluted tubule in the case of hydrochlorothiazide).[3,11] Thus water and sodium are secreted, with potassium being retained due to the action of triamterene. It is this potassium-sparing effect that is the primary reason for the addition of triamterene.[2] Hyperkalemia is a major side effect, and serum potassium must be monitored.

POTENTIAL PSYCHIATRIC SIDE EFFECTS

**** Decreased libido

**** Fatigue

(***) Self-induced water intoxication (in psychiatric

patients)

* Confusion

Discussion. Psychiatric effects are not a major concern with hydrochlorothiazide/triamterene, and few studies have been published in this area. There appears to be no substantial evidence for triamterene-stimulated psychiatric symptoms. In addition, no significant cognitive alterations were found in 24 adolescents on therapy with hydrochlorothiazide 25 to 50 mg three times per day.76 However, other antihypertensive agents are often known to be associated with sexual dysfunction, and such dysfunction occurs with HCTZ as well.[76] Decreased subjective sexual function was documented in 5 of 12 hypotensive men with no history of sexual dysfunction in a small placebo-controlled trial of HCTZ.[77]

Fatigue is not a psychiatric problem per se, but it can be a symptom of depression. In a postmarketing surveilance study of over 47,000 patients treated with triamterene/hydrochlorothiazide (Maxzide), no significant psychiatric changes were noted except for a 2% to 3% incidence of fatigue.[75]