Advertisements for clemastine (Tavist-1 - Sandoz), an ethanolamine oral antihistamine, have recently appeared on television and in major newspapers in the USA. Clemastine is an old drug (Medical Letter, 21:24, 1979) that has now become available without a prescription.

Botulinum toxin type A (Botox - Allergan) and type B (Myobloc - Elan) are now approved by the FDA for treatment of cervical dystonia. Botulinum toxin type A has been approved since 1989 for treatment of strabismus and blepharospasm. It is also used cosmetically to reduce wrinkles on the face and neck.

A patch formulation of oxybutynin (Oxytrol - Watson) is now available for treatment of overactive bladder. It is claimed to be as effective as the oral drug, with less dry mouth.

View the Comparison Chart: Some Drugs for Irritable Bowel Syndrome with Diarrhea (IBS-D)

Fluoxetine (Prozac - Dista), a phenylpropylamide, is the first serotonin-reuptake blocker introduced in the USA for treatment of . It is being promoted as causing fewer adverse effects than other antidepressants. Claims of greater safety and patient tolerability have often been made for new non-tricyclic antidepressants in recent years, but unpredicted adverse effects have emerged with widespread use, including priapism with trazodone (Desyrel - Medical Letter, 26:35, 1984) and fatal hemolytic anemia with nomifensine (Merital - Medical Letter, 27:73, 1985).

Acetaminophen (paracetamol; Tylenol, and others) taken in overdosage can cause severe hepatic injury and death. Acetaminophen poisoning is treated with (N-)acetylcysteine. Available for many years in the US as a solution for inhalation therapy (Mucomyst, and others), it subsequently became available for oral use and was recently marketed in the US for intravenous (IV) use as Acetadote (Cumberland).

An extended-release formulation of the centrally-acting muscle relaxant cyclobenzaprine (Amrix - Cephalon) has been approved by the FDA for treatment of muscle spasms. Immediate-release (IR) cyclobenzaprine (Flexeril, and others) has been available since 1977.

The FDA has approved a fixed-dose extended-release formulation of oxycodone and acetaminophen (Xartemis XR – Mallinckrodt) for oral treatment of acute pain severe enough to require an opioid. Oxycodone is available in the US as a single entity in oral immediate-release (Oxecta, and others) and extendedrelease (OxyContin) formulations. Immediate-release oxycodone is also available in combination with aspirin (Percodan, and others), acetaminophen (Percocet, and others), or ibuprofen (see Table 1).

The FDA has approved eluxadoline (Viberzi – Actavis), a mu-opioid receptor agonist and delta-opioid receptor antagonist, for oral treatment of adults with irritable bowel syndrome with diarrhea (IBS-D).

Rasagiline (Azilect - Teva), a monoamine oxidase-type B (MAO-B) inhibitor, was recently approved by the FDA for once-daily oral treatment of Parkinson's disease (PD). It can be taken alone for treatment of early disease or with levodopa/carbidopa (Sinemet, and others) for advanced disease. Selegiline (Eldepryl, and others), the first MAO-B inhibitor marketed in the US, has been available since 1988; a new lower-dose disintegrating tablet (Zelapar) was recently approved.