Name of Anti-Pruritic Drugs
- Cyproheptadine
- Calamine lotion
- Diphenhydramine
| Cyproheptadine |
| Availability: Syrup: 2 mg/5 ml Tablets: 4 mg |
| Indication & dosage: Allergy symptoms caused by histamine release (including seasonal and perennial allergic rhinitis); chronic urticaria; angioedema; dermographism; cold urticaria; adjunctive therapy for anaphylactic reactions Adults: Initially, 4 mg P.O. q 8 hours. Maintenance dosage is 4 to 20 mg/day in three divided doses, to a maximum dosage of 0.5 mg/kg/day. Children ages 7 to 14: 2 to 4 mg P.O. q 12 hours. Don’t exceed 16 mg/day. Children ages 2 to 6: 2 mg P.O. q 12 hours. Don’t exceed 12 mg/day. |
| Mechanism of Action: Antagonizes effects of histamine at histamine1-receptor sites, preventing histamine-mediated responses. Also blocks effects of serotonin, causing increased appetite |
| Contraindications: Hypersensitivity to drug ● Alcohol intolerance (syrup only) ● Bladder neck obstruction ● Angle-closure glaucoma ● Ulcer disease ● Symptomatic prostatic hypertrophy ● MAO inhibitor use within past |
| Metabolism & Elimination: Metabolized by glucuronidation via UGT1A Metabolites: Quaternary ammonium glucuronide conjugate Elimination Excretion: Urine (40%), feces (2-20%) |
| Administration: ● Give with food or milk to decrease GI upset. |
Precautions:
- hepatic impairment
- elderly patients
- pregnant patients (safety not established)
- breastfeeding patients.
Adverse reactions
CNS: drowsiness, dizziness, excitation (especially in children), fatigue, sedation, hallucinations, disorientation, tremor CV: palpitations, hypotension, arrhythmias
EENT: blurred vision, nasal dryness and congestion, dry throat
GI: constipation, dry mouth
GU: urinary retention, urinary frequency, ejaculatory inhibition, early menses
Respiratory: thickened bronchial secretions
Skin: rash, photosensitivity
Other: weight gain
Patient monitoring
- Monitor patient for excessive anticholinergic effects.
- Assess for excessive CNS depression.
- Discontinue drug 4 days before diagnostic skin testing.
Precautions:
- hepatic impairment
- elderly patients
- pregnant patients (safety not established)
- breastfeeding patients.
Adverse reactions
CNS: drowsiness, dizziness, excitation (especially in children), fatigue, sedation, hallucinations, disorientation, tremor CV: palpitations, hypotension, arrhythmias
EENT: blurred vision, nasal dryness and congestion, dry throat
GI: constipation, dry mouth
GU: urinary retention, urinary frequency, ejaculatory inhibition, early menses
Respiratory: thickened bronchial secretions
Skin: rash, photosensitivity
Other: weight gain
Patient monitoring
- Monitor patient for excessive anticholinergic effects.
- Assess for excessive CNS depression.
- Discontinue drug 4 days before diagnostic skin testing.
Patient teaching
- Advise patient to take drug with food to minimize GI upset.
- Caution patient not to use other CNS depressants, sleep aids, or alcohol during therapy.
Instruct patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.
As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, and behaviors mentioned above.
| Calamine lotion |
| Availability: topical lotion 1%/8% topical cream 1%/3% |
| Indication & dosage: Symptomatic treatment of pruritus Child and adult: one application 3 to 4 times daily in a thin layer |
| Mechanism of Action: Pramoxine: Local anesthetic due to inhibition of conduction of nerve impulses from sensory nerves, resulting from an alteration of the cell membrane permeability to ions |
| Contraindications: Hypersensitivity to any product component |
| Metabolism & Elimination: Absorption Onset: 3-5 min |
| Precautions: For external use only, Do not use in the eyes, Do not use on blistered or broken skin, If condition worsens, or if symptoms persist for longer than 7 days or clear up and occur again within a few days, discontinue use and reassess therapy, Do not apply to wounds or damaged skin., Do not bandage tightly, Keep out of reach of children; if swallowed, get medical help or contact a Poison Control Center immediately |
| Patient teaching Shake the lotion well before using., Moisten a pledget of cotton with the lotion., Use the moistened pledget to apply the lotion to the affected skin area(s). Allow the medicine to dry on the skin. |
| Diphenhydramine |
| Availability: Capsules: 25 mg, 50 mg Elixir: 12.5 mg/5 ml Injection: 10 mg/ml, 50 mg/ml Strips (orally disintegrating): 12.5 mg, 25 mg Syrup: 12.5 mg/5 ml Tablets: 25 mg, 50 mg Tablets (chewable): 12.5 mg, 25 mg Tablets (orally disintegrating): 12.5 mg |
| Indication & dosage: Allergy symptoms caused by histamine release (including anaphylaxis, seasonal and perennial allergic rhinitis, and allergic dermatoses); nausea; vertigo Adults and children over age 12: 25 to 50 mg P.O. q 4 to 6 hours, or 10 to 50 mg I.V. or I.M. q 2 to 3 hours p.r.n. (Some patients may need up to 100 mg.) Don’t exceed 400 mg/day. Children ages 6 to 12: 12.5 to 25 mg P.O. q 4 to 6 hours, or 1.25 mg/kg (37.5 mg/m2) I.M. or I.V. q.i.d. Don’t exceed 150 mg/day. Children ages 2 to 5: 6.25 mg P.O. q 4 to 6 hours. Don’t exceed 37.5 mg/day |
| Cough Adults: 25 mg P.O. q 4 hours p.r.n. Don’t exceed 150 mg/day. Children aged 6 to 12: 12.5 mg P.O. q 4 hours. Don’t exceed 75 mg/day. Children aged 2 to 5: 6.25 mg P.O. q 4 hours. Don’t exceed 37.5 mg/24 hours |
| Dyskinesia; Parkinson’s disease Adults: Initially, 25 mg P.O. t.i.d.; may be increased to a maximum of 50 mg q.i.d. |
| Mild nighttime sedation Adults: 50 mg P.O. 20 to 30 minutes before bedtime |
| Mechanism of Action: Interferes with histamine effects at histamine1-receptor sites; prevents but doesn’t reverse histamine-mediated response. Also possesses CNS depressant and anticholinergic properties |
| Contraindications: ● Hypersensitivity to drug ● Alcohol intolerance ● Acute asthma attacks ● MAO inhibitor uses within past 14 days ● Breastfeeding ● Neonates, premature infants |
Metabolism & Elimination:
Metabolized by liver (first pass)
Elimination
Half-life: 5 hr (children); 9 hr (adults); 13.5 hr (elderly)
Excretion: Urine (50-75%), mainly as metabolites
Administration:
- For motion sickness, administer 30 minutes before activity.
- For I.V. use, check compatibility before mixing with other drugs.
- Inject I.M. dose deep into large muscle mass, rotate sites.
- Discontinue drug 4 days before allergy skin testing to avoid misleading results.
- Don’t give within 14 days of MAO inhibitors
Precautions:
- severe hepatic disease, angle-closure glaucoma, seizure disorders, prostatic hypertrophy, cardiovascular disease, hyperthyroidism
- elderly patients
- pregnant patients (safety not established)
- children younger than age 2 (safety not established)
Adverse reactions
CNS: drowsiness, dizziness, headache, paradoxical stimulation (especially in children)
CV: hypotension, palpitations, tachycardia
EENT: blurred vision, tinnitus
GI: diarrhoea, constipation, dry mouth
GU: dysuria, urinary frequency or retention
Skin: photosensitivity
Other: decreased appetite, pain at I.M. injection site
Patient monitoring
- Monitor cardiovascular status, especially in patients with cardiovascular disease.
- Supervise patient during ambulation. Use side rails as necessary.
Patient teaching
- Advise patient to avoid alcohol and other depressants such as sedatives while taking drug.
- Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness. As appropriate, review all other significant adverse reactions and interactions, especially those related to the drugs, tests, herbs, and behaviours mentioned above.
REFERENCES
- Robert Kizior, Keith Hodgson, Saunders Nursing Drug handbook,1st edition 2024, Elsevier Publications. ISBN-9780443116070
- McGraw Hill- Drug Handbook, Seventh Edition, 2013, McGraw Hill Education Publications,9780071799430.
- April Hazard, Cynthia Sanoski, Davi’s Drug Guide for Nurses -Sixteenth Edition 2019, FA Davis Company Publications,9780803669451.
- Jones and Bartlet, Pharmacology for Nurses, Second Edition, 2020, Jones and Bartlet Learning Publications, ISBN 9781284141986.
- Nursebro.com, Search – Nursebro
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