A prescription-strength nonsteroidal anti-inflammatory gel for arthritis is the first of its kind to be approved for over-the-counter use in the United States, the drug maker announced this week.

Voltaren Arthritis Pain (diclofenac sodium topical gel, 1%) provides temporary relief of osteoarthritis pain in joints that respond to topical – or skin surface – treatment. These include the hand, wrist, elbow, foot, ankle or knee joints, according to GlaxoSmithKline.

The gel does not provide immediate relief and may take up to 7 days to reach full strength, according to the Food and Drug Administration. Users should discontinue the drug and talk to their doctor if arthritis pain is not improved in seven days or if they continue to need the product for more than 21 days, the agency said. It also cautioned that the drug’s active ingredient is linked to allergic reactions, especially in people allergic to aspirin.

However, the amount of diclofenac sodium that is absorbed into the body is on average 6% of what is absorbed by an oral form of diclofenac sodium, and the topical treatment provides people with osteoarthritis an alternative to oral NSAIDs, GSK said in its announcement.

GSK expects the gel to be available this spring. FDA originally approved the drug in 2007.