Also, salicylates may depress the concentration of prothrombin in the plasma. Salicylates may potentiate sulfonylurea hypoglycemic agents. Large doses of salicylates may have a hypoglycemic action, and thus, affect the insulin requirements of diabetics. Although salicylates in large doses are uricosuric agents, smaller amounts may depress uric acid clearance, and thus, decrease the uricosuric effects of probenecid, sulfinpyrazone and phenylbutazone. Sodium excretion produced by spironolactone may be decreased in the presence of salicylates.
Salicylates also retard the renal elimination of methotrexate.
Caffeine may cause nausea, nervousness, insomnia, headache, vomiting, palpitation, vertigo, muscle tremor, sensory disturbances, excessive diuresis in sensitive patients. Large doses may cause gastric ulceration. Severe cases may show fever, hemorrhage, excitement, confusion, convulsions or coma, and respiratory failure. Treatment is essentially symptomatic and supportive. Administer water, universal antidote and remove by gastric lavage or emesis.