C H A P T E R 5 4
Drugs acting on the upper respiratory tract
853
TABLE 54.3
DRUGS IN FOCUS Antihistamines (continued)
Drug name
Dosage/route
Usual indications
First-generation (continued)
dimenhydrinate
(Dimentabs, others)
Adult and paediatric (>12 years): 50–100 mg
PO q 4–6 hours or 50 mg IM as needed
Paediatric: <2 years: 1.25 mg/kg IM q.i.d.
2–6 years: 25 mg PO q 6–8 hours
6–12 years: 25–50 mg PO q 6–8 hours
Relief of nausea and vomiting associated
with motion sickness
diphenhydramine
(Benadryl, others)
Adult: 25–50 mg PO q 4–6 hours or 10–50 mg
IM or IV
Paediatric: 12.5–25 mg PO t.d.s. to q.i.d. or
5 mg/kg per day IM or IV
Use caution with geriatric people
Relief of symptoms of seasonal and
perennial allergic rhinitis, allergic
conjunctivitis, uncomplicated urticaria,
and angio-oedema; amelioration of
allergic reactions; relief of discomfort
associated with dermographism;
also used as adjunctive therapy in
anaphylactic reactions, as a sleeping aid,
and for parkinsonism
hydroxyzine (Vistaril,
others)
Adult: 25–100 mg PO t.d.s. to q.i.d. or
25–100 mg IM q 4–6 hours
Paediatric (>6 years): 50–100 mg/day PO in
divided doses
<6 years: 50 mg/day PO in divided doses or
1.1 mg/kg per dose IM
Relief of symptoms of seasonal and
perennial allergic rhinitis, allergic
conjunctivitis, uncomplicated urticaria,
and angio-oedema; amelioration of
allergic reactions; relief of discomfort
associated with dermographism; used
as adjunctive therapy in anaphylactic
reactions; also used for sedation
pheniramine (Avil)
Adult: Half of 45.3 mg tablet PO up to t.d.s.
increased to one tablet t.d.s. if necessary
Paediatric (5–10 years): Half of 45.3 mg tablet
PO up to t.d.s.
Relief of symptoms of seasonal and
perennial allergic rhinitis and conditions
of the respiratory tract where increased
secretions are present.
promethazine (Phenergan,
Avomine)
Adult: 25–50 mg PO, PR, IM or IV
Paediatric: 6.25–25 mg PO or PR
Relief of symptoms of seasonal and
perennial allergic rhinitis, allergic
conjunctivitis, uncomplicated urticaria,
and angio-oedema; ameliorates allergic
reactions; relief of discomfort associated
with dermographism; used as adjunctive
therapy in anaphylactic reactions; also
used for sedation
Second-generation (non-sedating)
azelastine (Azep)
One spray per nostril b.d.
Relief of symptoms of seasonal and
perennial allergic rhinitis
cetirizine (Zyrtec, Alzene)
Adult and paediatric (>12 years): 5–10 mg/
day PO; use 5 mg/day with hepatic or renal
impairment
Paediatric: 6–11 years: 5 or 10 mg/day PO
6 months–5 years: 2.5 mg PO q 12 hours or
5 mg/day PO
Relief of symptoms of seasonal and
perennial allergic rhinitis; management
of chronic urticaria
desloratadine
(Aerius,Claramax)
Adult and paediatric (>12 years): 5 mg/day PO
Paediatric: 6–11 years: 1 tsp, 2.5 mg/5 mL per
day PO
12 months–5 years: 1/2 tsp, 1.25 mg/2.5 mL
per day PO
6–11 mths: 1 mg/day PO
Hepatic or renal impairment: 5 mg PO every
other day
Relief of symptoms of seasonal allergic
rhinitis, chronic idiopathic urticaria
fexofenadine (Telfast)
Adult and paediatric (>12 years): 60 mg PO b.d.
Paediatric (6–11 years): 30 mg PO b.d.
Geriatric or renal-impaired person: 60 mg PO
every day
Relief of symptoms of seasonal and
perennial allergic rhinitis
Continued on following page
