What Factors Affect Humira® Dosage?

Humira® is a medication used to treat a broad spectrum of autoimmune diseases, or diseases caused by the body's own immune system mistakenly attacking its own cells. Also sold as the generic drug adalimumab, Humira® has been subjected to increasing scrutiny since its initial approval by the United States Food and Drug Administration for the treatment of rheumatoid arthritis. There are serious concerns that the use of Humira® and other tumor necrosis factor alpha blocking drugs may cause hepatosplenic T-cell lymphoma — an ordinarily rare and usually fatal form of leukemia — in children treated for autoimmune disorders. These medications have since been given a black box warning, alerting patients and prescribers that they increase the risk of developing serious bacterial, fungal, mycobacterial, viral and parasitic infection in multiple organ systems that may lead to hospitalization or death. Due to these very real risks, it is important to consider factors like the age, weight, and condition of the patient to determine the lowest possible effective Humira® dosage.

The standard Humira® dosage for polyarticular juvenile idiopathic arthritis is calculated primarily on the basis of weight. For patients between the ages of four and 17, weighing more than 66 lbs (30 kg), an Humira® dosage regimen of 40 mg by injection once every two weeks should be used. Pediatric patients that weigh between 33 lbs (15 kg) and 66 lbs (30 kg) should receive 20 mg of Humira® once per two-week period. While the medication has been used for patients weighing less than 33 lbs (15 kg), insufficient data exists to make a recommendation. The Humira® dosage is the same for patients receiving the drug as a monotherapy and with those receiving non-steroidal anti-inflammatory drugs, glucocorticoids or other analgesics as well.

In adult patients, the standard Humira® dosage for psoriatic arthritis, rheumatoid arthritis, or ankylosing spondylitis is the same as that of pediatric patients weighing over 66 lbs (30 kg): 40 mg by injection given once every two weeks. Patients receiving the medication alongside other medications to control pain and inflammation do not require adjustments to their dosage. Those not receiving methotrexate, however, may benefit from increasing the Humira® dosage to one injection per week.

Patients electing to use the medication for Crohn's disease should receive an initial breakthrough dose of 160 mg, given as either four injections of 40 mg in one day or two 40 mg injections on two consecutive days. After 14 days, two 40 mg injections should be administered. Another 14 days after this dose, the standard 40 mg maintenance regimen should be started, with subsequent 40 mg doses given every 14 days. The safety of this regimen for Crohn's disease treatment has not been evaluated for periods longer than one year.

The safety of Humira® for the treatment of plaque psoriasis has not been evaluated for periods longer than one year. As with Crohn's disease, an initial breakthrough dose is recommended. Two 40 mg injections should be administered on the first day of treatment. After 14 days, the standard adult maintenance dosage regimen of 40 mg administered once every two weeks should be used.