Anti Allergies
STEP 1:Indications of Anti Allergies:
Anti-allergies listed in essential medicine list include; Chlorpheniramine maleate, Cetirizine Hydrochloride, Loratadine, Promethazine hydrochloride, Adrenalin, Hydrocortisone, Dexamethasone and Calamine lotion.
Indications of drugs with anti-alergies properties are;
Chlorpheniramine maleate is used in symptomatic relief of allergy such as hay fever, urticaria; emergency treatment of anaphylactic reactions.
Cetirizine Hydrochloride, Loratadine are used in symptomatic relief of allergy such as hay fever and chronic idiopahtic urticaria.
Promethazine hydrochloride is used in symptomatic relief of allergy such as hay fever and urticaria; emergency treatment of anaphylactic reactions; sedation nausea and vomiting.
Adrenalin is used in emergency treatment of acute anaphylaxis, angioedema and cardiopulmonary resuscitation.
Hydrocortisone is used in adrenocortical insufficiency, hypersensitivity reactions e.g. anaphylactic shock and angioedema asthma, severe inflammatory bowel disease, haemorrhoids and rheumatic disease.
Dexamethasone is used in suppression of inflammatory and allergic disorders, diagnosis of Cushings disease, congenital adrenal hyperplasia, cerebral oedema associated with malignancy, nausea and vomiting with chemotherapy.
Calamine lotion is indicated for pruritus.
STEP 3: Contraindication of Anti-allergies:
Most individual drug which can be used as anti-allergies has different properties which make them to be contraindicated to patient with some specific conditions.
Chlorpheniramine maleate like many antihistamines it should be avoided in acute porphyria.
Cetirizine Hydrochloride and Loratadine like many antihistamines they should be avoided in acute porphyria they should also be avoided in pregnancy and breast-feeding.
Promethazine hydrochloride like many antihistamines it should be avoided in acute porphyria.
Hydrocortisone and dexamethasone are contraindicated to patients with systemic infection (unless specific therapy given): Live virus vaccines should also be avoided due to possible suppression of immunity because serum antibody response diminished)
STEP 4: Dose, Dosage and Course of Anti-allergies:
Chlorpheniramine maleate
By mouth, 4 mg every 4 to 6 hours, max. 24 mg daily Children, 12 years 1 mg twice daily; 26 years 1 mg every 4 to 6 hours, maximum 6 mg daily; 6 to 12 years 2 mg every 4 to 6 hours, max. 12 mg daily.
By intramuscular injection or by intravenous injection over 1 minute, 10 mg, repeated if required up to 4 times in 24 hours; CHILD under 6 months 250 micrograms/kg (max. 2.5 mg), repeated if required up to 4 times in 24 hours; 6 months6 years 2.5 mg, repeated if required up to 4 times in 24 hours; 6 to 12 years 5 mg, repeated if required up to 4
Cetirizine Hydrochloride and Loratadine
ADULT and CHILD over 6 years 10 mg once daily; CHILD 26 years 5 mg once daily.
Promethazine hydrochloride
By mouth, 10 to 20 mg 2 to 3 times daily; CHILDREN under 2 years not recommended, 2 to 5 years 5 to 15 mg daily in 1 to 2 divided doses, 5 to 10 years 10 to 25 mg daily in 1 to 2 divided doses.
By deep intramuscular injection, 255mg; max.100 mg; CHILD 5 to 10 years 6.25 to 12.5 mg.
By slow intravenous injection in emergencies, 25 to 50 mg as a solution containing 2.5 mg/mL in water for injections; max. 100 mg The drug should be administered twice daily for not more than five days
Adrenalin
Acute anaphylaxis, by intramuscular injection of 1 in 1000 (1 mg/mL) solution. Acute anaphylaxis when there is doubt as to the adequacy of the circulation, by slow intravenous injection of 1 in 10 000 (100 micrograms/mL) solution
Hydrocortisone
By mouth, replacement therapy, 20 to 30 mg daily in divided doses, CHILDREN 10 to 30 mg.
By intramuscular injection or slow intravenous injection or infusion, 100 to 500 mg, 3 to 4 times in 24 hours or as required; CHILDREN by slow intravenous injection up to 1 year 25 mg, 15 years 50 mg, 6 to 12 years 100 mg.
Dexamethasone.
By mouth, usual range 0.510 mg daily; CHILDREN 10100 micrograms/kg daily.
By intramuscular injection or slow intravenous injection or infusion (as dexamethasone phosphate), initially 0.524 mg CHILDREN 200 to 400 micrograms/kg daily Cerebral oedema associated with malignancy (as dexamethasone phosphate), by intravenous injection, 10 mg initially, then 4 mg by intramuscular injection every 6 hours as required for 24 days then gradually reduced and stopped over 57 days.
Calamine lotion should be applied occlusive to the affected part
STEP 5: Effects and Adverse Effects of Anti-Allergies:
Side and adverse effects of ant allergies.
Chlorpheniramine maleate and Promethazine Hydrochloride
Drowsiness, Headache,Psychomotor impairment,Antimuscarinic effects such as urinary retention, dry mouth, blurred vision, and gastro-intestinal disturbances.
Other rare side-effects of antihistamines include hypotension, palpitation, arrhythmias, extrapyramidal effects, dizziness, confusion, depression, sleep disturbances, tremor, convulsions, hypersensitivity reactions (including bronchospasm, angioedema, and anaphylaxis, rashes, and photosensitivity reactions) Dermatitis and tinnitus reported.
Cetirizine Hydrochloride and Loratadine.
Psychomotor impairment antimuscarinic effects such as urinary retention, dry mouth, blurred vision, and gastro-intestinal disturbances Other rare side-effects of antihistamines include hypotension, palpitation, arrhythmias, extrapyramidal effects, dizziness, confusion, depression, sleep disturbances, tremor, convulsions, hypersensitivity reactions (including bronchospasm, angioedema, and anaphylaxis, rashes, and photosensitivity reactions) .
Adrenalin
Nausea, vomiting, tachycardia, arrhythmias, palpitation, cold extremities, hypertension (risk of cerebral haemorrhage); dyspnoea, pulmonary oedema (on excessive dosage or extreme sensitivity); anxiety, tremor, restlessness, headache, weakness, dizziness; hyperglycaemia; urinary retention; sweating Tissue necrosis at injection site.
Hydrocortisone and Dexamethasone.
Mineralocorticoid side-effects include hypertension, sodium and water retention, and potassium and calcium loss Glucocorticoid side-effects include diabetes and osteoporosis which is a danger, particularly in the elderly, as it can result in osteoporotic fractures for example of the hip or vertebrae.
Other side-effects include: gastro-intestinal effects: dyspepsia, abdominal distension, acute pancreatitis, oesophageal ulceration and candidiasis Musculoskeletal effects: muscle weakness, vertebral and long bone fractures, tendon rupture Endocrine effects: menstrual irregularities and amenorrhoea, hirsutism, weight gain
Calamine lotion No reported side effect so far.
STEP 6: Interaction and Precaution of Anti-allergies
Drug interactions: Chlorpheniramine maleate, Cetirizine Hydrochloride, Loratadine and Promethazine hydrochloride being antihistamine when given with MAOI example phenelzine their sedative and antimuscarinic effects is increased.
Adrenalin no serious interaction
Hydrocortisone and Dexamethasone like other corticosteroids increases hematological effect of methotraxate.
Calamine lotion no serious interaction.
Precautions and cautions: Chlorpheniramine maleate, Cetirizine Hydrochloride, Loratadine and Promethazine hydrochloride should therefore be used with caution in prostatic hypertrophy, urinary retention, susceptibility to angle-closure glaucoma, and pyloroduodenal obstruction and in hepatic disease.
Adrenalin should be given with coution heart disease, hypertension, arrhythmias, cerebrovascular disease, phaeochromocytoma; diabetes mellitus, hyperthyroidism; susceptibility to angle-closure glaucoma; elderly
Hydrocortisone and Dexamethasone Abrupt withdrawal after a prolonged period can lead to acute adrenal insufficiency, hypotension or death Withdrawal can also be associated with fever, myalgia, arthralgia, rhinitis, conjunctivitis, painful itchy skin nodules and weight loss.
STEP 7: Key points (5 minutes) Antihistamine are common medicines in most allergic condition. Adrenaline is useful in emergence allergic condition like anaphylactic shock. Corticosteroid therapy should not be stopped abruptly Patient taking antihistamine should not drive or operate the machines.
STEP 7:References
Ministry of Health and Social Welfare. (2013).
Standard Treatment Guidelines & National Essential Medicines List Tanzania Mainland (4th ed.). Dar es salaam, Tanzania government printers.
Robert L. Talbert, Gary C. Yee, Gary R. Matzke, Barbara G. Wells, L. Michael. (2014). Pharmacotherapy: A Pathophysiologic Approach (9th ed.). New York, McGraw-Hill Education. Sally S.R, Jeanne C.S. (2000).
Introductory Clinical Pharmacology (6th ed) New York, Lippincott Williams and Wilkins. School of Pharmaceutical sciences. (2011).
Tanzania Pharmaceutical Handbook (2nd ed.). Dar es Salaam, ARDHI University press.
The Royal Pharmaceutical Society of Great Britain. (2007).
Martindale, The Extra Pharmacopoeia (5TH ed).
London, pharmaceutical press.
The Royal Pharmaceutical Society of Great Britain. (2009).
British National Formulary (59th ed). London, BMJ Group and RPS Publishing.
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