New drug for osteoarthritis patients

Around 40 per cent of Maltese senior citizens aged between 65 and 70 may have some degree of osteoarthritis, according to one of the country`s top physicians.

"Overall, taking the general population, up to 10 per cent have osteoarthritis. In Malta there is as high an incidence of osteoarthritis as there is in other countries," said Prof. Carmel Mallia consultant physician and rheumatologist at St Luke`s Hospital.

"We do not know the exact cause of the condition. Before, it was thought that it was the simple process of degeneration of the cartilage lining of the joint. Now we know it is a more complicated disease," he said.

The prevalence of osteoarthritis tends to increase with age and it can range from deformity in the digits, to limitation of joints, most commonly the spine, hip and knees.

Prof. Mallia was interviewed after a new remedy called Vioxx was launched in Malta recently after getting the green light from the US Food and Drug Administration.

This new drug, which is imported by local pharmaceutical company AM Mangion Limited, is said to have less of a negative impact on the stomach than other painkillers.

A UK survey of 3,000 osteoarthritis patients has found that of those who used the traditional medication, 58 per cent experienced indigestion; 31 per cent had nausea; 12 per cent, stomach ulcers and seven per cent had stomach bleeds.

These side effects are more likely to occur in elderly patients and in patients who had problems in the stomach or who are already taking certain medications.

Vioxx belongs to a new class of drugs called Cox-2 inhibitors that limit the inflammation of osteoarthritis without causing significant gastrointestinal problems.

"Cox-2 inhibitors, such as Vioxx, are an important development in arthritis treatment because unlike older drugs, they hardly have any effect on the stomach. However, as far as efficacy goes it is as effective as the previous drugs," Prof. Mallia said.

Despite being gentler on the stomach, Vioxx was recently under the spotlight after new research indicated that it could carry a higher risk of heart attacks.

The Vioxx Information Centre in the US reported that when compared with naproxen (Aleve), those taking Vioxx were much more likely to suffer a heart attack.

However, it said researchers were not sure whether this side effect was specific to Vioxx, or whether it was translated to all Cox-2 inhibitors.

Vioxx had immense benefits and it was very effective from the point of view of pain relief, and this small risk of heart attacks could be because Vioxx was different from naproxen in the way it affected platelets.

A drug such as naproxen, like aspirin, actually protects people from heart disease, so it was often recommended that those taking a low dose of aspirin should not discontinue taking it while concurrently taking Vioxx.

Prof. Mallia said that to understand this concept it was necessary to understand how non-steroidal anti-inflammatory drugs (NSAIDs) actually worked to help relieve pain and inflammation in arthritis.

NSAIDs, which come in tablet or liquid form, depending on the type prescribed, work to reduce the inflammation, pain and swelling of arthritis.

Exercise and a healthy lifestyle can help indirectly, because if you do not move the joints, the muscle weakens and the bulk diminishes making the joint more unstable.

Prof. Mallia said there were over 40 different NSAIDs, which have been in use for several years, and the majority were available in Malta.

These work to inhibit and limit the formation of prostaglandins, when the platelets stick together and form the beginning of a clot.

"Some of these drugs, especially aspirin, also inhibit the effect of thromboxane on the platelets, making them less sticky," he said.

The most common side effect of these drugs is stomach upsets as shown by the UK report. However, Vioxx attacks the inflammation without having a negative effect on the stomach.

American doctors who have delved into the properties of Vioxx believe that the possible explanation between the risk of a heart attack, could be in the simple difference between what enzymes are inhibited in the platelets by these drugs.

Prof. Mallia, like his counterparts abroad, believes that Cox-2 inhibitor drugs are an important advance in relieving pain in patients with arthritis.

However, these drugs may have other important side effects and Profs. Mallia strongly recommended that patients should always consult their doctor before taking any medication for osteoarthritis.