Treatment of Drug Allergy
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The offending drug must be immediately stopped. Most mild reactions (like skin rashes) subside by themselves and donot require specific treatment. Antihistamines (H1) are beneficial in some type I reactions (urticaria, rhinitis, swelling of lips, etc.) and some skin rashes.
TREATMENT OF DRUG ALLERGY
The
offending drug must be immediately stopped. Most mild reactions (like skin
rashes) subside by themselves and donot require specific treatment.
Antihistamines (H1) are beneficial in some type I reactions
(urticaria, rhinitis, swelling of lips, etc.) and some skin rashes. In case of
anaphylactic shock or angioedema of larynx the resuscitation council of UK has
recommended the following measures:
§ Put the patient in
reclining position, administer oxygen at high flow rate and perform
cardiopulmonary resuscitation if required.
§ Inject adrenaline 0.5
mg (0.5 ml of 1 in 1000 solution) i.m.; repeat every 5–10 min in case patient does
not improve or improvement is transient. This is the only life saving measure.
Adrenaline should not be injected i.v. (can itself be fatal) unless shock is
immediately life threatening. If adrenaline is to be injected i.v., it should
be diluted to 1:10,000 or 1:100,000 and infused slowly with constant
monitoring.
§ Administer a H1
antihistaminic (chlorpheniramine 10–20 mg) i.m./slow i.v. It may have adjuvant
value.
§ Intravenous
glucocorticoid (hydrocortisone sod. succinate 100–200 mg) should be added in severe/recurrent
cases. It acts slowly, but is specially valuable for prolonged reactions and in
asthmatics.
Adrenaline followed by a short course of
glucocorticoids is indicated for bronchospasm attending drug hypersensitivity.
Glucocorticoids are the only drug effective in type II, type III and type IV
reactions.
Drugs frequently causing allergic reactions
Drugs Frequently Causing
Allergic Reactions
Penicillins Salicylates
Cephalosporins Carbamazepine
Sulfonamides Allopurinol
Tetracyclines ACE inhibitors
Quinolones Methyldopa
Antitubercular drugs Hydralazine
Phenothiazines Local anaesthetics
Skin tests (intradermal, patch) or intranasal tests may forewarn in case of Type I
hypersensitivity, but not in case of other types. However, these tests are not
entirely reliable—false positive and false negative results are not rare.
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