Many of us might have experienced certain appreciably unpleasant or harmful reactions while or after being on certain medications of one or more classes of drugs to treat various forms of pain or disease conditions. These unwanted effects usually occur in the form of nausea, vomiting, diarrhea, headache, dizziness, sedation, loss of appetite, peptic ulcer, etc. But this is not the end of the list of unwanted effects! These effects at times may lead to hospitalization or at worse cases may take the life of the patient. Some of the life threatening adverse drug reactions (ADRs) are anaphylactic shock, kidney failure, liver dysfunction, haemolysis, arrhythmia, hypoglycemia, hypotension etc. As per reports from across the globe, ADRs approximately account for \u22655% of all hospital admissions. The unwanted effects that we encounter while on medications may be due to side effect of the drug or other adverse drug reactions. Side effects are predictable and usually not serious and are generally associated with the pharmacological profile of the drug and dose-dependent (increasing dose of a drug increases the side effect). For instance, codeine commonly used as a cough suppressant (antitussive) produces constipation as a common side effect. However, adverse drug reactions may either be predictable or unpredictable and are often more serious than side effects. Broadly, the definition of ADRs also includes reactions occurring as a result of error, misuse or abuse, and to any suspected reactions to medicine\/medicinal products at normal doses.
Patients are mainly unaware of the limitations of the premarketing phase of drug development in defining relatively common risks of new drugs. Only a few thousand patients are exposed to new experimental drugs in more or less well controlled and well-defined environment during drug development. Therefore, adverse drug effects that occur as frequently as just 1 in 1000 patients may not be detected prior to marketing of the drug. Additionally, it is well known that a population risk of 1 in 1000 patients is not distributed evenly across populations in different geographical areas; some patients because of their certain unique genetic makeup or environmental factors, are at an extremely high risk, while other population may be at low or no risk at all. Hence, post marketing surveillance (PMS) which is the practice of monitoring for any adverse drug reactions post clinical trial of a drug after it has been released on the market is imperative to detect infrequent adverse drug effects. This is a very crucial practice as limited information on rare ADRs are available for the safety and efficacy evaluation of any new medicinal products through the processes in clinical trial phase. Therefore, understanding of any effects associated with use of medicines and more specifically for those medicines which we get direct access from a pharmacy without medical prescription (over-the-counter drugs) such as analgesics\/ painkillers, antidiarrhoeals, anti-allergy, and even antibiotics (mainly during COVID pandemic) etc., is crucial to minimize unnecessary exposure to the drugs to reduce the extent of damage to the body, if any ADRs occur, and also to avoid exposure to the same drug in the future. Unfortunately, there is no way to completely avoid all types of ADRs because the drug alone is not the sole determinant of the ADRs but multiple factors are also involved. Among the many factors which contribute to ADRs, genetic diversity (differences in genetic makeup between individuals), physiological and pathological conditions of the individual (like pre- existing diseases), environmental factors which include food-drug interactions or drug-drug interaction, etc. are significant notable factors.
One easy way to reduce the incidence of ADRs at an individual level is avoiding self-medication and maintaining of high level compliance to prescription (meaning correctly following as per medical prescription). As per a report, only about 50% of patients follow the prescribed dosage regimen in reasonably satisfactory fashion; and 1 in 6 patients is noncompliant. Of course, missed doses are more common than too many doses. Furthermore, continuing of any medication beyond the prescribed period may not be safe and is to be avoided as far as possible. In the event of a need to continue treatment, it is prudent to consult a physician so as to avoid further unnecessary exposure to the same medicine. As for instance, consumption of commonly available painkillers- Non-steroidal anti inflammatory drugs (NSAIDs) for an extended period of time to manage chronic pain and fever often lead to chronic renal failure (kidney failure), liver damage and most commonly development of stomach\/peptic ulcer. Such unwanted effects associated with painkillers in human are not an exception in veterinary medicine. Cases are being reported with owners of animals inadvertently using painkillers in an inappropriately higher dose or for a prolonged period of time without complying with the prescribed dosage regimen provided by the veterinarian. The dose of a drug differs from species to species in animals, which is mainly attributed to differences in their body size as well as their genetic makeup. Certain classes of drugs are found to be highly sensitive and prone to toxicity in some species of animals. As an example, cats are prone to ADRs and toxicity with drugs such as paracetamol and other NSAIDs, morphine, diazepam, pentobaritone, chloramphenicol, etc. Deficiency of certain drug metabolizing enzymes (mainly enzymes involved in glucoronidation of drugs) found in liver of cats as compared to other species of animals is mainly responsible for many ADRs in this species. It is advised not to extrapolate and use dose of a drug prescribed for a dog to a cat or vice versa for the aforementioned reason. Thus, veterinarians takes utmost precautions to avoid ADRs and toxicity while administering certain drugs in sensitive species by making appropriate adjustment in dosage regimen, which may be in the form of reduction of dose or using an alternate drugs.
ADRs can occur following administration of any class of medicines. However, our emphasis in this article is mainly on ADRs associated with the use of NSAIDs. This class of drug is one of the most widely used drugs in human and animals. NSAIDs like ibuprofen, aspirin, diclofenac, etc., with the exception of paracetamol, even though these are important and commonly prescribed, can irritate the stomach lining and often produce peptic ulcer and even perforation of gastric mucosa in serious cases, if not treated on time. The main reason being that their actions are not target specific. These drugs not only reduce pain, fever and inflammation, but also reduce the level of vital biochemicals \u2013such as prostanoids in the stomach which are essential for protection of the gastric mucosa against gastric acid secretions. Taking such medicines after food is a simple and good way to reduce the chance of development of peptic ulcer by avoiding direct contact of the drug with stomach wall. An article published in the Daily Mail on 8th February 2020 entitled \u201cHeart disease alert over the long-term use of paracetamol\u201d clearly mentioned the increased risk of heart attack and stroke by 20% in human as a consequence of increased blood pressure associated with the use of paracetamol and other NSAIDs. Chronic renal failure associated with the prolonged use of NSAIDs results in reduced blood flow to kidney due to reduced prostaglandins synthesis leading to reduced kidney function (reduced glomerular filtration rate) and ultimately chronic renal failure. There are many novel classes of painkiller that are comparatively less likely to produce such unwanted adverse effects and can be used for longer period. Undergoing regular blood biochemical tests to determine any damage to kidney, liver and other organs are highly recommended in case of prolong medication with any class of drug.
Overall the main focus of this short article on ADRs is to enlighten the importance of maintaining a high level of compliance to prescription so as to prevent or reduce the risk of development of any potentially harmful or unpleasant reactions associated with medications.
Dr. Wangkheirakpam
Ramdas Singh, PhD & Dr. Soya Rungsung, PhD, Department of Pharmacology & Toxicology, College of Veterinary Sciences & Animal Husbandry, CAU, Jalukie, Nagaland.<\/p>\n","protected":false},"excerpt":{"rendered":"
Many of us might have experienced certain appreciably unpleasant or harmful reactions while or after being on certain medications of one or more classes of drugs to treat various forms of pain or disease conditions. These unwanted effects usually occur in the form of nausea, vomiting, diarrhea, headache, dizziness, sedation, loss of appetite, peptic ulcer, […]<\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[],"tags":[],"class_list":["post-250545","post","type-post","status-publish","format-standard"],"_links":{"self":[{"href":"https:\/\/nagalandpost.net\/index.php\/wp-json\/wp\/v2\/posts\/250545","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/nagalandpost.net\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/nagalandpost.net\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/nagalandpost.net\/index.php\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/nagalandpost.net\/index.php\/wp-json\/wp\/v2\/comments?post=250545"}],"version-history":[{"count":0,"href":"https:\/\/nagalandpost.net\/index.php\/wp-json\/wp\/v2\/posts\/250545\/revisions"}],"wp:attachment":[{"href":"https:\/\/nagalandpost.net\/index.php\/wp-json\/wp\/v2\/media?parent=250545"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nagalandpost.net\/index.php\/wp-json\/wp\/v2\/categories?post=250545"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nagalandpost.net\/index.php\/wp-json\/wp\/v2\/tags?post=250545"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}