Rofecoxib, a cox-2inhiditor pain killer was introduced to treat adverse effect of are to avoid adverse effect of NSAIDS like stomach ulcers unfortunately it use was associated with cardio vascular events like cardio vascular and stroke. Like Trastuzumab, Clozapine also cause cardio vascular diseases.
The word drug induced diseases sounds like a paradox. A drug induced disease is the unintended effect of a drug which results in mortality or morbidity with symptoms sufficient to promote a patient to seek medical attention and require hospitalization. Drug induced disease can result from un anticipated or anticipate drug effect .Disease also can occur from product impurities, patient is necessary to minimize the potential harm that is inherent in drug use.
Adverse drug reactions are a reality. Then why do we use drugs? Drugs are approved for use only if their potential benefits far outweigh the risk involved. Also, not all people react similarly to a drug. It is possible that particular drug ,while completely benefiting some people may cause potentially life threatening adverse effects.
The world health organisation defines an adverse drug reaction as any noxious, unintentional, and undesired effect of a drug, which occurs at doses used in humans for prophylaxis, diagnosis, or therapy.
Medical occurrence temporally associated with the use of a medicinal product, but not necessarily casually related. the essential difference from ADR(Adverse drug reaction) is that AE(Adverse event) need not be casually related to the drug.
UNEXPECTED ADVERSE REACTION:
Usually adverse drug reactions of a drug will be described in the product information. UAR is not consistent with applicable product information or characteristics of drug.
Unintended effect occurring at normal dose related to pharmacological properties.
SERIOUS ADVERSE EVENT:
Any untoward medical occurrence that at any dose results in death, life threatening situation, requires in patient hospitalization or prolongation of existing hospitalization, results in deformity or incapacity. SAE (Serious adverse event) is especially important when you are doing drug trail/drug development.
SERIOUS UNEXPECTED SUSPECTED ADVERSE REACTION:
It is adverse drug reaction which is suspected but unexpected and serious.
TYPES OF DRUG INDUCED DISEASES:
Disease caused by drugs can be either predictable or unpredictable. predictable effects are extension of normal pharmacological effects of the drug. for example blood thinners (anticoagulant and anti platelet drugs) that are used to prevent clotting of blood in cause bleeding as a side effect. Several anti diabetes medication like insulin and sulfonylureas can cause low blood glucose levels.
On the other hand, unpredictable effects are completely and related therapeutic effect of the drug. For example, amiodarone, a drug used to treat abnormal heart rhythms, Can cause lung damage. Drug induced diseases may be classified as mild, moderate, severe, or lethal based on their severity. Drug induced diseases can effect various organ system of the body. Some examples according to the organ system affected.
CARDIO VASCULAR SYSTEM:
SKIN: The skin is the most obvious part of the body, and therefore any reaction is easily noticed. Drug induced reactions are may be acute or chronic.Acute reaction may vary from a simple rash and to a serious condition.
· A special type of skin reaction caused by drugs is called fixed drug eruption, here, the skin lesions appears only on a particular part. Fixed drug reactions noted with, barbiturates and Sulphonamides. The blood thinner warfarin can rarely cause necrosis of the skin. Hydralazine and procainamide cause a chronic immunologic reaction called SLE like symptom that also effect the musculoskeletal system,kidneys and the brain. Sulphonamides, chloroquine and tetracycline can produce a photosensitive reaction
BRAIN AND NERVES:
· The anti tuberculosis drug isoniazide or INH interferes with the utilisation of vitamin B6 and cause neurological symptoms ranging from peripheral neuritis, mental disturbances Theophylline, an anti asthma medication, if not maintain within normal levels in the blood, can cause neurological symptoms like restlessness and tremors, which may also progress to seizures along with abnormal heart rhythms and shock.
· Drugs used for treatment of cancer, Methotrexate and leomycin cause scarring of the lungs called pulmonary fibrosis or interstitial pneumonitis. The patient suffers from breathlessness and non productive cough, which can worsen if the dosage is not lowered. Amiodarone is an non anti cancer drug that also damages the lung. Aspirin and non selective beta blockers like Propronolol can cause an asthma like condition, making it difficult for the patient to breathe.
· Non steroidal pain killers and corticosteroids are well known to cause stomach ulcers, especially when taken an empty stomach. Bisphosphonates used in the treatment of osteoporosis can cause esophageal ulcers and are advised to be taken in an upright position.
Diarrhoea can be caused by nearly every oral drug. Iron salt and loperamide can cause constipation. Drugs can affect different parts of the kidney causing a number of kidney disorders. these include Glomerulonephritis which may be caused by drugs like penicillin, NSAIDs, gold ,lithium.
HOW TO DIAGNOSE DRUG INDUCED DISEASES:
· These are primarily diagnosed based on the history of drug intake obtained from the patient.
· The symptoms should appear at a reasonable time frame after taking the medication.
· The physicians should enquire about drug intake to any patient coming to the clinic with the problem so as not to miss out on a drug-induced disease. If the drug is re-administered the symptoms may reappear
· If the symptoms are re appeared than the drug induced disease was confirmed.
· The first step in the treatment of drug induced diseases is to report the adverse effect to the physician who may stop the intake of medication or at times, reduce the dose gradually, and replace with an appropriate alternative. Many times, this simple step can relive the patient of the symptoms. Those who do not recover require additional treatment depending upon adverse event.
· Steps that could help prevent a drug induced disease including the following:
Always inform your doctor if you suffer from any illness or take any other medication including a nutritional supplement before you are prescribed a medication. Inform your doctor if you have suffered from any previous allergic reaction to a drug or any other substances like food ingredients.
Take the medication only as prescribed by the doctor. Adhere to the dose and duration of treatment.
M. Keerthi Kumari, S. Sai sushma
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