BISMUTH SUBSALICYLATE

Chemistry - Bismuth subsalicylate occurs as white or nearly white, tasteless, odorless powder andcontains about 58% bismuth. It is insoluble in water, glycerin and alcohol. It may also be known asbismuth salicylate, or bismuth oxysalicylate.

Storage, Stability, Compatibility

Bismuth subsalicylate should be stored protected from light.
It is incompatible with mineral acids and iron salts. When exposed to alkali bicarbonates, bismuthsubsalicylate decomposes with effervescence.

Pharmacology - BISMUTH SUBSALICYLATE

Bismuth subsalicylate is thought to posses protectant, anti-endotoxic and weakantibacterial properties. It is believed that the parent compound is cleaved in the small intestine intobismuth carbonate and salicylate. The protectant, anti-endotoxic and weak antibacterial propertiesare thought to be as a result of the bismuth. The salicylate component has antiprostaglandin activitywhich may contribute to its effectiveness and reduce symptoms associated with secretory diarrheas.

Uses, Indications

In veterinary medicine, bismuth subsalicylate products are used to treat diarrhea. The drug is also used in humans for other GI symptoms (indigestion, cramps, gas pains) andin the treatment and prophylaxis of traveler's diarrhea.

Pharmacokinetics - BISMUTH SUBSALICYLATE

No specific veterinary information was located. In humans, the amount ofbismuth absorbed is negligible while the salicylate component is rapidly and completely absorbed.
Salicylates are highly bound to plasma proteins and are metabolized in the liver to salicylic acid.
Salicylic acid, conjugated salicylate metabolites and any absorbed bismuth are all excreted renally.
Contraindications/Precautions - Salicylate absorption may occur; use with caution in patientswith preexisting bleeding disorders. Because of the potential for adverse effects caused by thesalicylate component, this drug should be used cautiously, if at all, in cats.

Adverse Effects, Warnings

Antidiarrheal products are not a substitute for adequate fluid andelectrolyte therapy when required. May change stool color to a gray-black or greenish-black; do notconfuse with melena. In human infants and debilitated individuals, use of this product may causeimpactions to occur.
As bismuth is radiopaque, it may interfere with GI tract radiologic examinations.
Overdosage - No specific information located, but theoretically may cause salicylism. See the
Aspirin monograph for more information.

Drug Interactions

Bismuth containing products can decrease the absorption or orally administered tetracycline products. If both agents are to be used, separate drugs by at least 2 hours andadminister tetracycline first.
Because bismuth subsalicylate contains salicylate, concomitant administration with aspirin mayincrease salicylate serum levels; monitor appropriately.
Laboratory Test Interference - At high doses, salicylates may cause false-positive results forurinary glucose if using the cupric sulfate method (Clinitest®, Benedict's solution) and false-negative results if using the glucose oxidase method (Clinistix® or Tes-Tape®). Urinary ketonesmeasured by the ferric chloride method (Gerhardt) may be affected if salicylates are in the urine(reddish-color produced). 5-HIAA determinations by the fluoremetric method may be interfered bysalicylates in the urine. Falsely elevated VMA (vanillylmandelic acid) may be seen with mostmethods used if salicylates are in the urine. Falsely lowered VMA levels may be seen if using the
Pisano method. Urinary excretion of xylose may be decreased if salicylates are given concurrently.
Falsely elevated serum uric acid values may be measured if using colorimetric methods.