New drugs 98: Part III

Nursing, Jun 1998 by Hussar, Daniel A

Irbesartan may be administered once a day without regard to meals. If irbesartan alone doesn't adequately control BP, the practitioner may add a low dose of a diuretic such as hydrochlorothiazide.

A patient with volume or salt depletion (for example, someone receiving high doses of diuretics) may experience symptomatic hypotension. If he must begin treatment with irbesartan before the depleted condition is corrected, his initial dosage should be lower.

The new drug may cause fetal and neonatal injury or death if used during the second or third trimesters of pregnancy. If a woman being treated with irbesartan becomes pregnant, stop treatment as soon as possible.

Irbesartan isn't available in Canada or Australia.

Drug for canker sores

AMLEXANOX

Soothing pesky

Aphthous ulcers, commonly known as canker sores, are painful ulcers of the oral mucosa that occur in up to 25% of the general population. The ulcers typically last for 7 to 14 days and may recur. No specific cause of the ulcers is known, but some data implicate a localized immune reaction.

Amlexanox (Aphthasol, Block Drug), a prescription adhesive oral paste, is the first medication to be approved for the local treatment of aphthous ulcers in patients with normal immune systems. Patients with human immunodeficiency virus infection frequently develop aphthous ulcers, but the drug isn't presently indicated for them because its effectiveness and safety haven't been established in immunocompromised patients.

No serious local or systemic adverse reactions have been reported with the topical use of amlexanox. Up to 2% of patients experienced transient pain, stinging, or burning at the site of application.

Amlexanox oral paste is supplied as a 5% concentration in 5-gram tubes. Tell your patient to apply the paste to the ulcer site as soon as she notices symptoms. Tell her to squeeze about 1/4 inch of paste onto a fingertip and gently press it onto each ulcer. She should wash her hands immediately after applying the paste. She should use it four times a day-after breakfast, lunch, and dinner and at bedtime (preferably after brushing her teeth).

She should continue treatment with amlexanox until the ulcer heals. Advise her to contact her dentist or physician if significant healing or pain reduction hasn't occurred in 10 days. Amlexanox isn't available in Canada or Australia.

Antiodote

FOMPIZOLE

Putting the chill on antifreeze poisoning

Fomepizole (Antizol, Orphan Medical) is the first drug to be approved as an antidote for ethylene glycol poisoning or for use in suspected ethylene glycol ingestion. Over 5,500 exposures to ethylene glycol, the main component of antifreeze and coolants, were reported in 1996. If not treated promptly, poisoning with this substance may result in CNS depression, severe metabolic acidosis, renal failure, coma, and death. Ethanol has also been used to treat ethylene glycol poisoning; however, fomepizole is less likely to cause CNS depressant reactions.

Fomepizole inhibits the metabolism of ethylene glycol, blocking the formation of its toxic metabolites. Besides treatment with fomepizole, patients must be managed for possible metabolic acidosis, acute renal failure, acute respiratory distress syndrome, and hypocalcemia. Dialysis should be considered in patients with renal failure, significant or worsening metabolic acidosis, or a measured ethylene glycol concentration of greater than 50 mg/dl.