As with any medication, there is some risk with long-term use of adalimumab (Humira). However, its safety profile is quite good.

Adalimumab is an injectable "biologic" treatment for rheumatoid arthritis, psoriatic arthritis, other types of arthritis, and colitis (colon inflammation). It's called a biologic because it acts against a naturally occurring substance (tumor necrosis factor) that promotes inflammation. Other biologic agents that act in a similar way include etanercept (Enbrel) and infliximab (Remicade). These are called anti-TNF drugs. (The TNF is for "tumor necrosis factor.")

You are quite right about the link to tuberculosis (TB). However, that's a problem primarily in people who have been exposed to TB in the past. That's why doctors check for TB before starting a patient on these drugs. If a skin test is positive, a chest X-ray and full examination are performed to look for active infection. No one with active TB should receive an anti-TNF drug. For those with a positive skin test but no active infection, antibiotic treatment is available to reduce the risk of TB while taking adalimumab.

Other possible side effects of adalimumab use include:

• Allergic and immune reactions
• Reactivation of hepatitis B among people who carry this virus
• Nerve injury that may mimic multiple sclerosis
• Low blood counts
• Increased risk of certain cancers (primarily skin cancers and lymphoma, a cancer of the lymph nodes; the magnitude of this increased risk is under considerable debate)
• Worsening of heart failure

Just last week, the Food and Drug Administration alerted doctors that serious fungal pneumonias had been linked to the use of anti-TNF treatment. However, these appear to be quite rare.

Despite the number of potentially serious side effects, their rate is quite low. And for most of them, there's no clear link with long-term use. For example, when TB complicates anti-TNF treatment, the infection often occurs soon after starting the drug.

If you have concerns about any of the medications you take, talk to your doctor. Your risks may be higher or lower than average based on your overall health, the other medicines you take and where you live.