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).

Short-acting methylphenidate (MPH) is effective for treatment of attention-deficit/hyperactivity disorder (ADHD), but its 3-5 hour duration of action usually requires mid-day dosing in school, which children may find disruptive or stigmatizing.

Deep brain stimulation (DBS) is increasingly used to treat advanced Parkinson's disease (PD), but few controlled clinical trials have been published. New evidence from a large controlled study has recently become available.

Sexual complaints related to desire, arousal, orgasm and painful intercourse are common in women. Since the last Medical Letter article on this subject, some new information has become available.

Cannabis (marijuana) contains more than 60 pharmacologically active cannabinoids; delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) are the best known. THC is the main psychoactive constituent of cannabis. CBD, unlike THC, does not produce intoxication or euphoria.

Many different drugs are used for treatment of osteoarthritis pain, but none of them prevent progression of the disease. Nonpharmacologic approaches including weight management, exercise, tai chi, physical therapy, assistive devices, and total joint arthroplasty can also be used. The American College of Rheumatology (ACR) has published new guidelines for the management of osteoarthritis of the hip, hand, and knee.

The motor symptoms of Parkinson's disease (PD) are caused primarily by degeneration of dopaminergic neurons in the substantia nigra. The nonmotor symptoms of the disease are thought to be caused by degeneration of other neurotransmitter systems. No disease-modifying drugs are available for treatment of PD.

Intrauterine devices (IUDs) and the etonogestrel implant are the most effective reversible contraceptive methods available. Hormonal oral contraceptives, patches, rings, and injectables are also effective in preventing pregnancy. When used alone, barrier and behavioral methods generally have higher failure rates than other methods (see Table 1). Selection of a contraceptive method is usually based on patient-specific factors and personal preference

When used for the appropriate seizure type, antiseizure medications (ASMs) are roughly equivalent in efficacy. In addition to the seizure type, the choice of drug is usually based on factors such as ease of use, spectrum of activity, adverse effects, interactions with other drugs, presence of comorbid conditions, suitability for elderly persons and those with childbearing potential, and cost. Treatment should begin with a single drug, increasing the dosage gradually until seizures are controlled or adverse effects become unacceptable. If seizures persist, expert clinicians generally...