Drug Interactions between losartan and SymlinPen 60

GENERALLY AVOID: Moderate-to-high dietary intake of potassium, especially salt substitutes, may increase the risk of hyperkalemia in some patients who are using angiotensin II receptor blockers (ARBs). ARBs can promote hyperkalemia through inhibition of angiotensin II-induced aldosterone secretion. Patients with diabetes, heart failure, dehydration, or renal insufficiency have a greater risk of developing hyperkalemia.

MANAGEMENT: Patients should receive dietary counseling and be advised to not use potassium-containing salt substitutes or over-the-counter potassium supplements without consulting their physician. If salt substitutes are used concurrently, regular monitoring of serum potassium levels is recommended. Patients should also be advised to seek medical attention if they experience symptoms of hyperkalemia such as weakness, irregular heartbeat, confusion, tingling of the extremities, or feelings of heaviness in the legs.

MONITOR: Grapefruit juice may modestly decrease and delay the conversion of losartan to its active metabolite, E3174. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits. The clinical significance is unknown. Moreover, pharmacokinetic alterations associated with interactions involving grapefruit juice are often subject to a high degree of interpatient variability.

MANAGEMENT: Patients who regularly consume grapefruits and grapefruit juice should be monitored for altered efficacy of losartan. Grapefruits and grapefruit juice should be avoided if an interaction is suspected. Orange juice is not expected to interact.

ADJUST DOSING INTERVAL: Pramlintide slows gastric emptying and may delay the absorption of concomitantly administered oral medications. In a pharmacokinetic study of 24 patients with type 2 diabetes, coadministration with pramlintide (120 mcg) decreased the peak plasma concentration (Cmax) of acetaminophen (1000 mg) by 29% and increased its time to peak plasma concentration (Tmax) based on the time of acetaminophen administration relative to pramlintide injection. Pramlintide significantly increased acetaminophen Tmax (range 48 to 72 minutes) when acetaminophen was administered simultaneously with or up to 2 hours following pramlintide injection, but it had negligible effect when acetaminophen was administered 1 to 2 hours before pramlintide injection.

MANAGEMENT: When rapid onset of a concomitantly administered oral medication is critical to its effectiveness, the medication should be administered at least 1 hour before or 2 hours after pramlintide injection.