View the Expanded Table: Some Oral Drugs for Chronic Insomnia

To avoid the morbidity and occasional mortality of transurethral resection or open prostatectomy, some urologists are now using balloon dilatation of the prostatic urethra to treat benign prostatic hypertrophy.

The FDA has approved lemborexant (Dayvigo – Eisai), an orexin receptor antagonist, for treatment of sleep-onset and/or sleep-maintenance insomnia in adults. It is the second orexin receptor antagonist to be approved for this indication; suvorexant (Belsomra) was the first.

Several currently available antiemetic drugs can prevent vomiting caused by cancer chemotherapy. Anticancer drugs that cause vomiting are listed in the table below.

Ropinirole (Requip - GlaxoSmithKline), a dopamine agonist already available for treatment of Parkinson's disease, is now the first drug approved by the FDA for treatment of moderate to severe restless legs syndrome (RLS).

Opioids, benzodiazepines, propofol, antipsychotics and dexmedetomidine (Precedex) are frequently used in the intensive care unit (ICU) to manage pain, anxiety, agitation and delirium, and to facilitate procedures such as mechanical ventilation. The use of dexmedetomidine, a centrally-acting selective α₂-receptor agonist approved by the FDA in 1999, has been increasing in recent years. Some new studies comparing it to other drugs for ICU sedation have been published.

Older patients are especially susceptible to drug-induced cognitive impairment. They are more likely to be taking multiple drugs, to have higher blood levels of those drugs because of renal or hepatic dysfunction, and to have pre-existing cognitive problems that make it difficult to detect the role of drugs causing new symptoms or making old ones worse.

Nabilone (Cesamet - Lilly), a synthetic cannabinoid chemically related to tetrahydrocannabinol (THC), the main active ingredient in marijuana, was recently marketed in the USA for oral treatment of nausea and vomiting associated with cancer chemotherapy. Oral THC itself, known generically as dronabinol (Marinol), is also commercially available as an antiemetic for cancer patients (Medical Letter, 27:97, 1985). Other drugs used for this purpose include metoclopramide (Reglan - Medical Letter, 24:67, 1982), prochlorperazine (Compazine; and others), haloperidol (Haldol; and others), and...

Clozapine (Clozaril - Sandoz), an antipsychotic drug, was first marketed in the USA three years ago (Medical Letter, 32:3, 1990). Because of its hematological toxicity, the US Food and Drug Administration approved the drug only for patients with schizophrenia who cannot tolerate or do not respond to standard antipsychotic drugs.

Serious adverse interactions between drugs continue to be reported. Many of these are due to inhibition or induction of cytochrome P450 (CYP) enzymes, particularly CYP3A4. CYP3A is thought to be involved in the metabolism of more than 50 percent of currently prescribed drugs.2 CYP3A4, which is more abundantly expressed than CYP3A5, accounts for most CYP3A activity in vivo.