Some commonly used systemic drugs that may cause pulmonary toxicity are listed in the table below. These adverse effects may sometimes be difficult to distinguish from the underlying disease (JAD Cooper, Jr et al, Am Rev Respir Dis, 133:321, 488, 1986). Pulmonary effects that are part of a generalized reaction or are indirect effects of drugs - on respiratory muscles, for example, or on the immune system - are not included here.

Changes caused by one drug in the absorption, distribution, metabolism or excretion of another may lead to a pharmacokinetic adverse drug interaction (DN Juurlink et al, JAMA 2003; 289:1652). Additive drug interactions, such as vasodilation caused by both sildenafil (Viagra) and nitrates, can also have adverse effects.

Until the recent introduction of febuxostat (Uloric), no new drugs had been marketed for treatment of gout in the past 40 years. Colchicine, which has been available for decades as an unapproved drug, has now been approved by the FDA (Colcrys) for treatment and prophylaxis of gout flares. It was approved earlier only in combination with probenecid (Colbenemid, and others). The goals of gout treatment are three-fold: treating acute disease, preventing flares and reducing uric acid stores.

As the weather becomes warmer, physicians may see more photosensitivity reactions due to systemic or topical drugs, perfumes, cosmetics or sunscreens. Even brief exposure to sunlight in warm or cold weather can cause intense cutaneous reactions in patients with drug-induced photosensitivity, and some patients may continue to be sensitive to sunlight long after stopping use of the offending agent.

Oxaprozin (Daypro -Searle), a propionic acid-derivative nonsteroidal anti-inflammatory drug (NSAID), has been approved by the US Food and Drug Administration for once-daily treatment of rheumatoid arthritis and osteoarthritis. Some of the NSAIDs previously marketed in the USA are listed in the table on page 16. Ibuprofen, naproxen, fenoprofen, ketoprofen, and flurbiprofen are also propionic acid derivatives. Piroxicam and nabumetone (Medical Letter, 34:38, 1992) are also approved for once-daily use, and indomethacin is available in an extended-release formulation that can be taken once...

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 severity and rapid spread of COVID-19 (caused by SARS-CoV-2) have raised questions about the use of some drugs in patients with the disease and whether currently available drugs could be effective in treating it. Definitive answers are lacking, but some recommendations can be made. For additional information on specific drugs, see our table Some Drugs Being Considered for Treatment of COVID-19.

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.

Drugs for gout are used to reduce the pain and inflammation of acute flares, decrease the frequency of exacerbations, and lower serum urate levels to prevent recurrent flares, development of tophi, and joint damage.

View the Table: Treatments Considered for COVID-19