Drug Interactions between galantamine and troleandomycin

Galantamine should be taken with food, and you should drink plenty of fluids throughout the day to reduce the severity of certain side effects such as nausea, vomiting, diarrhea, loss of appetite, and/or weight loss. Extended-release formulations should be swallowed whole (i.E., do not crush, chew, or divide the pill) and are often recommended to be taken in the morning. You should speak with your healthcare provider before using grapefruit products (fruit, juice, supplements) with galantamine as they may increase the blood levels and side effects of galantamine. You should also contact your healthcare provider if you experience changes in your heart rate, seizures, difficulty breathing, trouble urinating, dizziness, fainting, nausea, vomiting, diarrhea, and/or unexpected weight loss. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

Due to their pharmacological action, cholinesterase inhibitors can have a vagotonic effect on the sinoatrial and atrioventricular nodes producing bradycardia or heart block. Therapy with cholinesterase inhibitors should be administered cautiously in patients with preexisting bradycardia or underlying cardiac conduction abnormalities. Syncopal episodes have been reported. Atropine may be used to reverse bradycardia produced by cholinesterase inhibitors.

Cholinesterase inhibitors inhibit the hydrolysis of acetylcholine. The enhanced effect of acetylcholine produces constriction of the bronchi, increased bronchial secretions, and bronchospasm. Therapy with cholinesterase inhibitors should be administered cautiously in patients with respiratory dysfunction, history of asthma, or obstructive pulmonary disease. Respiratory function should be closely monitored for the occurrence of respiratory adverse reactions. Use of atropine along with discontinuation of the cholinesterase inhibitor may be required for serious respiratory distress.

Troleandomycin is primarily excreted by the liver and may accumulate in patients with impaired hepatic function. In addition, the use of troleandomycin has been associated with an allergic type of cholestatic hepatitis, particularly in patients receiving the drug for more than 2 weeks or given repeated courses. Therapy with troleandomycin should be administered cautiously in patients with liver and/or biliary disease. Liver function tests should be monitored during prolonged or repeated courses of therapy, and the drug discontinued if abnormalities develop.

Cholinesterase inhibitors inhibit the hydrolysis of acetylcholine. The enhanced effect of acetylcholine produces constriction of the bronchi, increased bronchial secretions, and bronchospasm. Therapy with cholinesterase inhibitors should be administered cautiously in patients with respiratory dysfunction, history of asthma, or obstructive pulmonary disease. Respiratory function should be closely monitored for the occurrence of respiratory adverse reactions. Use of atropine along with discontinuation of the cholinesterase inhibitor may be required for serious respiratory distress.

Clostridioides difficile-associated diarrhea (CDAD), formerly pseudomembranous colitis, has been reported with almost all antibacterial drugs and may range from mild diarrhea to fatal colitis. The most common culprits include clindamycin and lincomycin. Antibacterial therapy alters the normal flora of the colon, leading to overgrowth of C difficile, whose toxins A and B contribute to CDAD development. Morbidity and mortality are increased with hypertoxin-producing strains of C difficile; these infections can be resistant to antimicrobial therapy and may require colectomy. CDAD must be considered in all patients who present with diarrhea after antibacterial use. Since CDAD has been reported to occur more than 2 months after antibacterial use, careful medical history is necessary. Therapy with broad-spectrum antibacterials and other agents with significant antibacterial activity should be administered cautiously in patients with history of gastrointestinal disease, particularly colitis; pseudomembranous colitis (generally characterized by severe, persistent diarrhea and severe abdominal cramps, and sometimes associated with the passage of blood and mucus), if it occurs, may be more severe in these patients and may be associated with flares in underlying disease activity. Antibacterial drugs not directed against C difficile may need to be stopped if CDAD is suspected or confirmed. Appropriate fluid and electrolyte management, protein supplementation, antibacterial treatment of C difficile, and surgical evaluation should be started as clinically indicated.

Troleandomycin is primarily excreted by the liver and may accumulate in patients with impaired hepatic function. In addition, the use of troleandomycin has been associated with an allergic type of cholestatic hepatitis, particularly in patients receiving the drug for more than 2 weeks or given repeated courses. Therapy with troleandomycin should be administered cautiously in patients with liver and/or biliary disease. Liver function tests should be monitored during prolonged or repeated courses of therapy, and the drug discontinued if abnormalities develop.

In patients with moderate hepatic impairment (Child-Pugh score of 7 to 9), the dosage of galantamine or benzgalantamine should generally not exceed 16 mg/day or 20 mg/day, respectively. The use of galantamine or benzgalantamine in patients with severe hepatic impairment (Child-Pugh score of 10 to 15) is not recommended.

The use of cholinesterase inhibitors is associated with an increase in gastric acid secretion and gastric contractions. Monitor for symptoms of active or occult gastrointestinal bleeding, especially in patients at increased risk for developing ulcers (e.g., history of ulcer disease or concurrent use of nonsteroidal anti-inflammatory drugs).

In patients with creatinine clearance of 9 to 59 mL/min, the dosage of galantamine or benzgalantamine should generally not exceed 16 mg/day or 20 mg/day, respectively. In patients with creatinine clearance less than 9 mL/min, the use of galantamine or benzgalantamine is not recommended.

Cholinesterase inhibitors have been associated with convulsions and tremor. Therapy with cholinesterase inhibitors should be administered cautiously in patients with seizure disorders. Patients with Alzheimer's disease should be closely monitored for seizures.