Drug Interaction Report

MONITOR: Coadministration of 5-aminosalicylate with other nephrotoxic agents may increase the risk and severity of renal impairment due to additive effects on the kidney. The use of 5-aminosalicylate or its prodrugs has been associated with rare reports of renal impairment including minimal change nephropathy, acute and chronic interstitial nephritis, and renal failure. Animal studies have also shown the kidney to be the major target organ of 5-aminosalicylate toxicity. Renal lesions including granular and hyaline casts, tubular degeneration, tubular dilation, renal infarct, papillary edema, papillary necrosis, tubular necrosis, interstitial fibrosis, and interstitial nephritis have been observed with large doses.

MANAGEMENT: Caution is advised when 5-aminosalicylate preparations are prescribed to patients who have recently received or are receiving treatment with other potentially nephrotoxic agents (e.g., aminoglycosides; polypeptide, glycopeptide, and polymyxin antibiotics; amphotericin B; adefovir; cidofovir; foscarnet; cisplatin; deferasirox; gallium nitrate; lithium; certain immunosuppressants; intravenous bisphosphonates; intravenous pentamidine; high intravenous dosages of methotrexate; high dosages and/or chronic use of nonsteroidal anti-inflammatory agents). Renal function should be evaluated prior to and during 5-aminosalicylate therapy.

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.

MONITOR: One study has suggested that caffeine withdrawal may significantly increase blood lithium levels. The mechanism may be involve reversal of a caffeine-induced increase in renal lithium excretion.

MANAGEMENT: When caffeine is eliminated from the diet of lithium-treated patients, caution should be exercised. When caffeine consumption is decreased, close observation for evidence of lithium toxicity and worsening of the psychiatric disorder is recommended. Patients should be advised to notify their physician if they experience symptoms of possible lithium toxicity such as drowsiness, dizziness, weakness, ataxia, tremor, vomiting, diarrhea, thirst, blurry vision, tinnitus, or increased urination.