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7 Cards in this Set
- Front
- Back
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What class of drug is diclofenac? |
Pregnancy category C A non steroidal anti-inflammatory analgesic fenamate- non selective COX inhibtor |
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How diclofenac works in the pain pathway |
Diclofenac binds to and inhibits the action of COX enzymes in the body. This binding is reversible. By inhibiting COX-2 enzyme, the formation of prostaglandins and thromboxane from arachidonic acid is inhibited. COX= an enzyme thats responsible for the formation of such mediators as prostaglandins. By inhibiting this enzyme you can relieve symptoms of inflammation and pain. Eg NSAID such as ibuprofen/aspirin NSAIDs act mainly in the periphery. Injured and inflamed tissues release mediators such as 5TH and bradykinin with the outcome of nociceptors activation. PGs may also play a role in facilitating transmission of pain impulses through the spinal cord. By inhibiting the formation of PGs diclofenac reduces nociception and transmission of pain impulses through the CNS. |
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what are the risks of taking diclofenac during the different stages of pregnancy? |
COX inhibitors and the fetus- COX is a potent dilator of the ductus arterioles and pulmonary resistance vessels. Inhibition of COX has the potential of causing premature closing of the vessels. Some studies have indicated an increased risk of miscarriage in the first trimester - the suggestion being that they may interfere with the implantation process due to effects of the prostaglandin pathway. Use of NSAIDs after 30/40 is contraindicated because of their potential to cause premature closure of the metal ductus arteriosus and persistent pulmonary hypertension. High dose of NSAIDs in the 3rd trimester may also reduce perfusion of the metal kidneys and decrease fetal urine output. Category C pregnancy drug - drugs which owing to their pharmacological effects, have caused or may be suspected of causing, harmful effects on the human foetus without causing malformations. These effects may be reversible |
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State the pharmacokinetic effects of sustained release formulations of a drug |
Sustained release tablet- pharmaceutical preparation in which the drug is released into the GIT over varying lengths of time. Identified by SR on the container. This can be achieved by : active matrix of drug can be embedded in an inert substance which disintegrates gradually in the gut, releasing the drug slowly. |
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Advantages/disadvantages to Rosie of receiving the drug in this form |
Advantages: uniform release of drug substance over time, reduction in frequency of intakes, reduced adverse side effects, better patient compliance, often a reduction in overall dose required for therapeutic effect. Disadvantages: suboptimal window of release - can be considerable variation in the disintegration and thus absorption of the drug - possibly due to variation in the transit time through the GIT, also what foods eaten, variations in the pH of the gut. Slow onset, low peak, take care not to crush or chew |
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What does Rosie need to be told with regards to this type of tablet? |
These need to be taken whole not crushed or broken - could lead to initial overdosing and later drug dropping below therapeutic levels between doses. |
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Explain how the pharmacodynamics of diclofenac can cause symptoms of indigestion |
Acts via COX-1 inhibition --> interference with normal regulation of acid and bicarbonate/mucus secretion in the stomach. In the presence of diclofenac, there is decreased protective mucus/bicarbonate layer and increased acid secretion. This combination can cause inflammation of the stomach wall and lead to symptoms of indigestion including pain, acid reflux, nausea and epigastric discomfort. |
