Drug Approvals
(BANM, US Adopted Name, rINNM)
International Nonproprietary Names (INNs) in main languages (French, Latin, and Spanish):
Pharmacopoeias. In British.
BP 2008 (Carbenoxolone Sodium). A white or pale cream-coloured, hygroscopic powder. Freely soluble in water sparingly soluble in alcohol practically insoluble in chloroform and in ether. A 10% solution in water has a pH of 8.0 to 9.2.
Adverse Effects, Treatment, and Precautions
Carbenoxolone sodium has mineralocorticoid-like effects and ingestion may produce sodium and water retention and hypokalaemia. This may cause or exacerbate hypertension, heart failure, oedema, alkalosis, and muscle weakness and damage, and systemic carbenoxolone should therefore be used with caution, if at all, in patients with cardiovascular disease. If hypokalaemia is prolonged, renal impairment can occur.
Care is needed in preexisting hepatic or renal impairment. Regular monitoring of weight and blood pressure is advised if hypokalaemia, oedema, or a significant rise in blood pressure occurs, carbenoxolone therapy should be stopped. Potassium depletion may be corrected with potassium supplements. Systemic use of carbenoxolone sodium is contra-indicated in patients with hypokalaemia, in pregnancy, in the elderly, and in children.
Muscle weakness, muscle necrosis, myopathy, hypertension, headache, cardiac failure, mental confusion, areflexia, renal tubular dysfunction, and acute tubular necrosis have all been associated with carbenoxolone-induced hypokalaemia. Carbenoxolone-induced hypertension may have precipitated the onset of fatal polyarteritis in a patient predisposed to this condition.
Handling
Carbenoxolone sodium powder is irritant to nasal membranes.
Interactions
Because of the risk of toxicity, carbenoxolone should not be taken with digitalis glycosides unless serum-electrolyte concentrations are measured at weekly intervals and precautions are taken to avoid hypokalaemia.
Although amiloride or spironolactone relieve sodium and water retention, they antagonise the efficacy of systemic carbenoxolone and should not be used with it. The hypokalaemia associated with diuretics may be exacerbated by carbenoxolone.
Pharmacokinetics
Carbenoxolone sodium is absorbed from the gastrointestinal tract, mainly from the stomach. It is highly bound to plasma proteins. Carbenoxolone is chiefly excreted in the faeces via the bile. It appears to undergo enterohepatic circulation.
Uses and Administration
Carbenoxolone sodium is a synthetic derivative of glycyrrhizic acid that was formerly used as a mucosal protectant in peptic ulcer disease and has been given with antacids and alginic acid in gastro-oesophageal reflux disease.
Carbenoxolone sodium is one of many topical treatments for the symptomatic management of mouth ulceration. It is usually used as a 2% gel a 1 % mouthwash has been used.
Mental function
High cortisol concentrations have been associated with poorer memory and neuronal loss in some patients. Carbenoxolone inhibits 11-p-hydroxysteroid dehydrogenase type 1, and thus may selectively lower intracellular cortisol. In a small crossover study in 10 healthy elderly men, carbenoxolone 100 mg three times daily by mouth for 4 weeks significantly improved verbal fluency compared with placebo, but did not influence visual or verbal memory, nonverbal reasoning, or processing speed.
Twelve patients with stable type 2 diabetes were given carbenoxolone at the same dose for 6 weeks. Verbal memory was significantly improved compared with placebo, but verbal fluency and other scores were unaltered. All subjects were given amiloride lOmg daily to prevent miner aloe orticoid adverse effects (but see Interactions, above).
Preparations
Proprietary Preparations
Australia:: Bioral
Austria: Rowadermat
Hong Kong: Herpesan
Hungary: Carbosan
Ireland: Carbosan
Malaysia: Herpesan
Philippines: Rowagel
Singapore Herpesan
Spain: Sanodin
UK: Bioplex Bioral.
Multi-ingredient
Ireland: Pyrogastrone
UK: Pyrogastrone
Jennifer is a clinical pharmacologist. She helps doctors of all medical specialties choose medications. Jennifer consults about drug dosage, interactions, and side effects.