Antidepressants are effective in alleviating osteoarthritis pain, according to doctors in the US.

The mood medication can play a key role in alleviating the painful condition and may result in fewer side effects than traditionally prescribed drugs, such as anti-inflammatories.

American doctors analysed duloxetine, which is a well-established antidepressant used to treat chronic musculoskeletal pain, including osteoarthritis.

Dr Leslie Citrome and her colleague Dr Amy Weiss-Citrome of New York Medical College looked at studies exploring the effects of duloxetine being used on its own or in combination with non-steroidal anti-inflammatory drugs (NSAIDs).

The side effects of the various drugs were taken into account. NSAIDs can lead to gastrointestinal bleeding, and opiates such as morphine, which can cause constipation.

In comparison, the most common side effects of duloxetine - nausea, fatigue and constipation - were less severe.

The researchers studied 524 patients over a ten-week period. All participants had osteoarthritis of the knee. The doctors discovered that those who took a combination of duloxetine and NSAIDs reported greater pain reductions than the control group who took a NSAID with a placebo.

"It is not uncommon to treat osteoarthritis with a combination of drugs that work in different ways," said Dr Leslie Citrome.

"Our review supports this approach and confirms that antidepressants are not just for depression and can play a key role in relieving this painful condition."

The report was published in the International Journal of Clinical Practice.