When medication becomes a double-edged sword

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It is ironic that some medications, popular for their availability, affordability and effectiveness in treating common disease like malaria can cause life-threatening reactions when taken in the right dosage. 

 

Do you now realise the importance of knowing which drugs or chemical elements you react to? Many times, health specialists ask patients whether they react to a particular compound such as sulphur and many do not even stop to question why. 

 

Other times, people self-medicate probably because the drug once helped them cure a disease, but did you know that you can react to a drug that you successfully used before?  

 

Most genuine medications are enclosed in leaflets with basic information about a drug, the possible side-effects and what to do in case of complications, but how often do we read this information?

 

What is adverse drug reaction?

According to the World Health Organisation (WHO), an adverse drug reaction is an unintended, harmful reaction to medicines taken in a normal dose. 

Helen Ndagije, the head of the Drug Information Department at National Drug Authority (NDA), adds that: "A drug reaction can only be referred to as adverse, after investigations to rule out other possible causes of the discomfort have been carried out."

 

Adverse drug reactions can result from an undetected medical, allergic or genetic condition. 

 

Dr. Moses Miti, a general practitioner at the Emergency Medical Department, Mulago Hospital, says one's genetic makeup can determine how one react to a drug. 

 

"For instance, if your sister reacts to drugs with sulphur, such as Sulfadoxine/pyrimethamine (fansidar) or Co-trimoxazole (Septrin), you are likely to react the same way because you are genetically related." He adds that those who react to sulphur drugs can even react to other products containing sulphur, for instance, skin lotions.

 

Victoria Bukenya, a regulatory officer in charge of drug safety at the National Pharmacovigilance Centre, NDA, says depending on one's genetic makeup, some people may metabolise or process the drugs slowly, which leads to drug accumulation in the body, causing toxicity, hence an adverse reaction.

 

Ndagije adds that some people may not be able to manufacture enzymes that break down the drugs or certain foods, hence making the medicine harmful.

 

 

Some adverse drug reactions, according to Bukenya, result from immune disorders where one's system detects a drug as a foreign body and triggers antibodies to fight it. 

 

 

Misdiagnosis of a health condition and self-medication can cause adverse drug reactions. When a doctor prescribes the wrong drug or gives the wrong dosage, one can react to the drug. 

 

Sometimes, failure to follow medical instructions may result in drug reaction. "For example, if a doctor advises that you take coartem with fatty foods, or that you eat before taking medication, if you do otherwise, the medicine may react negatively," Ndagije says.

 

 

Medications, whose composition and ingredients do not meet the recommended requirements can be dangerous. 

"There are also many counterfeit drugs on the market.

 

For instance, some people package Septrin in Paracetamol wraps, or they substitute Flagyl for Quinine. This can result in fatal complications, especially if the medication is taken by one who reacts to certain chemicals used in some drugs," Bukenya says.

 

 

The degradable by-products in drugs can spark off adverse effects if poorly stored.

 

 

According to Ndagije, other factors can influence one's chances of having an adverse drug reaction. These include; age, body mass, underlying diseases, type of food one eats and taking different drugs concurrently.

 

 

Miti says reactions to medications could be minor or life-threatening. However, people react differently. The symptoms range from a rash to blisters.

 

According to NDA, symptoms of drug reactions include; vomiting, hair loss, drop in blood pressure, stomach cramps, diarrhoea, body rash and cough. Others are nausea, high blood pressure, swelling of the face,  throat and mouth, difficulty in swallowing or speaking, alterations in the heart rate, abdominal pain, sudden body weakness, loss of consciousness, stuffy nose, wheezing and shock.

 

Bukenya says sulphur-containing drugs, which include sulfadoxine/pyrimethamine (fansidar) or co-trimoxazole (septrin) are commonly known for causing the Stevens-Johnson syndrome.

 

Stevens-Johnson syndrome is a life-threatening hypersensitive disorder which causes the skin and mucous membranes to react severely to a medication or infection, Bukenya says. It may start with flu-like symptoms, then painful read eyes, sore throat, lips and mouth, blisters, eroding or shedding off the skins.

 

According to the National Pharmacovigilance Centre, although beta-lactam antibiotics are available, cost effective, the population is increasing becoming hypersensitive to them.

 

Beta-lactam antibiotics include; Cefalosporins (Cefuroxime, Cephalosporins  etc) and Penicillins (Amoxicillin-Clavulanate, Piperacillin and Penicillin V). 

 

These medications are useful in treating diseases of the upper respiratory tract and infections including; pneumonia, urinary tract infections, cardiovascular infections and skin infections, 

 

Macrolides (typical antibiotics) like azithromycin, although known for treating common bacterial infections like ear infections, sore throat, pneumonia, typhoid and sinusitis, experts say these may increase the risk of cardiovascular conditions.

 

ARVs like Nevirapin and Atazanavir Sulfate have registered a number of negative reactions. 

According to NDA, adverse effects associated with Atazanavir Sulfate may affect the liver, metabolism, stomach and intestines, skin, blood, heart, kidney and immunity.

 

Nambasa says cancer drugs can cause anaemia, while common drugs like chloramphenicol may suppress the born marrow, affecting the formation of red bloods cells. "This can cause blood cancer." 

 

Nambasa also notes that prolonged use of pain killers like paracetamol, aspirin and ibuprofen can poison the liver.

 

According to Ndagije, anyone who takes medication is at risk of reacting to it. "Unfortunately, most adverse reactions are not documented or are forwarded to NDA late. Therefore, medicine safety issues may not be dealt with expeditiously," she adds.

 

 

NDA records reveal that 124 victims of adverse drug reactions were registered between January and August 2012. Mbale reported 10 cases, Butabika Hospital (Kampala) 9, Rukungiri 6, Kabale 3, Kibaale 15, Wakiso 1, Soroti 3, Mbarara 5, Bushenyi 1, Rakai 2, Mubende 3, Masaka 34, Lyantonde 7, Kasese 1, Kabarole 3, Kalungu 12, Lwengo 4, Mukono 3, Hoima 2 and Buyende 2. 

 

 

According to the World Health Organisation, about 60% of adverse drug reactions can be prevented. 

Miti says a patient should stop taking the medicine immediately one notices any reaction and should see a health professional immediately.

 

Nambasa advises everyone to be cautious and report any drug reaction to a health worker, however minor it may seem.

"The most important thing is for patients to get as much information as possible on their health status and treatment," Ndagije notes. 

 

She also advises patients to read the leaflets enclosed in the drug packets, as these carry useful information on the drug and the possible side-effects.

 

Miti cautions against self-medication and encourages patients to search for information on drugs. "Patients should gather as much information as possible from their doctors." He says in developed countries, people carry with them cards showing the drugs, compounds or foods they react to. It helps, therefore, that you carry this information with you all the time.

 

In addition, Nambasa advises health workers to keep track of patients' drug history. "Patients are entitled to knowing what they're being treated with. Therefore it's the role of the health workers to document and avail patients with their medical records." 

 

Ndagijje advised patients to take seriously the prescriptions and to always follow up with the health workers because one can keep track of when the reaction is expected. The patient's information may help other health professionals too when it comes to diagnosis.

 

Miti also advised patients to always give feedback, whether good or bad, to their health workers, as helps them keep track of a patient's health history.

 

People should also get personal doctors to closely follow up on their health at all times.

Nambasa appeals to patients never to shun taking medicine, but instead take it under health workers' instructions and supervision and to immediately report any reaction, however minor it may seem.

 

She adds that health professionals should take reporting any suspected adverse drug reactions as part of their daily patient care. 

 

 

Unintended, harmful reactions to medicines (known as adverse drug reactions) are among the leading causes of death in many countries.

 

Most adverse drug reactions are preventable.

 

People in every country of the world are affected by adverse drug reactions.

 

In some countries, adverse drug reaction-related costs, such as hospitalisation, surgery and lost productivity, exceed the cost of the medications.

 

No medicine is risk-free. Vigilant assessment of the risks and benefits of medicines promotes patient safety.

 

See a qualified health provider when you notice any of these symptoms after taking medicine: 

Drowsiness

Confusion

Breathing difficulties

Skin rash or

Itching

Swelling of body parts

Headache

Dry mouth

Severe nausea and vomiting

Diarrhoea

Constipation

Bleeding

Any unusual reaction.

 

 

 

NDA says it has increasingly engaged various stakeholders to increase awareness on the importance of improving the quality of healthcare

 

Also, in order improve reporting adverse drug reactions, NDA in conjunction with the STD/STI Control Programme, adopted targeted spontaneous reporting of adverse drug reactions, focusing on Tenofovir-based regime and drugs used for prevention of mother-to-child-transmission. 

 

This is meant to improve care and safety of patients on antiretroviral therapy in Uganda to provide data for future reference on the safety of Tenofovir and drug use in prevention of mother-to-child-transmission of HIV. 

 

It is also intended to enhance science and the activities relating to detection, assessment, understanding and prevention of adverse effects or any other drug-related problems in public health programmes and among health professionals in Uganda.

 

The National Pharmacovigilance Centre, NDA, also established centres in regional referral hospitals, which has helped increase health workers' vigilance in patient safety.

 

The centres are also required to forward adverse drug reaction reports to NDA for future reference and healthcare improvement.

 

Compiled by Brenda Nakayiwa