Drug Interactions between haloperidol and Kalexate

GENERALLY AVOID: Alcohol may potentiate some of the pharmacologic effects of CNS-active agents. Use in combination may result in additive central nervous system depression and/or impairment of judgment, thinking, and psychomotor skills.

MANAGEMENT: Patients receiving CNS-active agents should be warned of this interaction and advised to avoid or limit consumption of alcohol. Ambulatory patients should be counseled to avoid hazardous activities requiring complete mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.

GENERALLY AVOID: Potassium in foods can bind to the cation exchange resin and interfere with potassium removal in the treatment of hyperkalemia.

MANAGEMENT: Cation exchange resins should not be mixed with orange juice or other foods with a high potassium content.

ADJUST DOSING INTERVAL: Cation exchange resins may bind to other medications that are administered orally. Reduced systemic absorption and therapeutic efficacy may occur. Manufacturers have reported that polystyrene sulfonate exchange resins can decrease the absorption of lithium and levothyroxine. A more recent study found that sodium polystyrene sulfonate binds to many commonly prescribed oral medications. Another potassium-lowering drug, patiromer, has also been found to bind about half of the medications tested, some of which are commonly used in patients who require potassium-lowering drugs.

MANAGEMENT: To minimize the risk of interaction, patients should be advised to separate the dosing of the cation exchange resin from other orally administered medications by at least 3 hours. The dosing interval should be increased to 6 hours for patients with gastroparesis or other conditions resulting in delayed emptying of food from the stomach into the small intestine. Health care professionals should monitor blood levels and/or clinical response to the other medications when appropriate.

ADJUST DOSING INTERVAL: Simultaneous administration of cation-donating preparations may reduce the potassium exchange capability of cation-exchange resins due to binding of the cation to the resin.

MANAGEMENT: Patients should consider separating the times of administration of the cation-exchange resin and any cation-donating preparation (e.g., mineral supplements; antacids; products containing antacids such as didanosine buffered tablets or pediatric oral solution) by several hours if possible.

MONITOR: Smoking cessation may lead to elevated plasma concentrations and enhanced pharmacologic effects of drugs that are substrates of CYP450 1A2 (and possibly CYP450 1A1) and/or certain drugs with a narrow therapeutic index (e.g., flecainide, pentazocine). One proposed mechanism is related to the loss of CYP450 1A2 and 1A1 induction by polycyclic aromatic hydrocarbons in tobacco smoke; when smoking cessation agents are initiated and smoking stops, the metabolism of certain drugs may decrease leading to increased plasma concentrations. The mechanism by which smoking cessation affects narrow therapeutic index drugs that are not known substrates of CYP450 1A2 or 1A1 is unknown. The clinical significance of this interaction is unknown as clinical data are lacking.

MANAGEMENT: Until more information is available, caution is advisable if smoking cessation agents are used concomitantly with drugs that are substrates of CYP450 1A2 or 1A1 and/or those with a narrow therapeutic range. Patients receiving smoking cessation agents may require periodic dose adjustments and closer clinical and laboratory monitoring of medications that are substrates of CYP450 1A2 or 1A1.