Meloxicam is a nonsteroidal anti-flammatory drug (NSAIDs) which are a group of drugs to treat pain and/or inflammation. It is an only prescription drug and is available for individuals who have tenderness, swelling and pain caused by the inflammation of osteoarthritis, rheumatoid arthritis or ankylosing spondylitis. Meloxicam functions by inhibiting the effect of chemicals called cyclo-oxygenase (COX) enzymes which are used to make prostaglandins. Prostaglandins are the chemicals that cause pain and inflammation, known as inflammation mediators. By inhibiting the COX enzymes, fewer prostaglandins are produced, resulting in relief of pain. As there are many conditions that has to be followed up when prescribing a drug, this essay will discuss the following based on Meloxicam:
• Absorption and distribution of the drug
• Use of drug in pregnancy and breastfeeding
• Use of drug in renal and hepatic impairment
Absorption and distribution of the drug
The absorption of Meloxicam through oral administration is from the gastrointestinal tract which results in a high availability of 89%. This can be in the form of tablets, oral suspension and capsules and will produce the same bioavailability. However, with different forms of Meloxicam, there will be a difference in the time taken for the mean maximum plasma concentrations to be achieved. Following a single dose of taking Meloxicam in oral suspension form, the mean maximum plasma concentration is achieved in 2 hours whereas for capsules and tablets, it takes about 5-6 hours. This is more effective when taking a single oral dose of 30mg compared with 30 mg IV bolus injection. Dose proportional pharmacokinetics were shown in the range of 5mg to 60 mg when taking single intravenous doses. With multiple dosing, steady state conditions were achieved within 3-5 days. Particularly when following ‘after multiple oral doses, the pharmacokinetics of Meloxicam capsules were dose-proportional over the range of 7.5mg to 15mg.’1 Commonly, it takes about 5-6 hours for the tablets, capsule and oral suspension to reach steady state of maximum plasma concentration when taking Meloxicam. It is also noted that absorption of Meloxicam is not altered by concomitant food intake.
Meloxicam is ‘99% bound to plasma proteins…has a plasma-elimination half-life of about 20 hours.’2 This makes it easy for once-daily administration which allows improvement for treatment of chronic rheumatic diseases and as well as contributing to clinical benefits achieved from uninterrupted therapy. The plasma protein that Meloxicam binds to is albumin within the therapeutic dose range. Meloxicam is distributed out ‘after biotransformation to 4 pharmacologically inactive metabolites, which are excreted in urine and faeces.’3 Within 6 hours, Meloxicam is well absorbed after oral or rectal doses and peak plasma concentrations will occur. Most patients with renal failure will find a decrease of about 99% of the binding of protein which is...