Emergency drugs

        ACICLOVIR

Antiviral.Inhibits Dna polymerase only in infected cells;needs activation by viral thymidine kinase(produce by Herpes spp.)

Uses

Severe Hsv or Vzv infection e.g meningitis,encephalitis and in immunocompromised patients

Po/top-mucous membrane,genitals,eye infection.

Caution

ARF

Encephalopathy

Hypersensitivity

GI disorder,skin reaction,non-specific neurological symptom,blood disorder.

Interaction

Levels inc.by probenecid

Dose

5mg/kg tds i/v over 1 hr.(10mg/kg if HSV encephalitis or VSV in immunocompromised pt.)

Adrenaline

Sympathomimetic:powerful stimulation of alpha(vasoconstrictor),beta1(inc.HR,inc.contractility)and beta2(vasodilation,bronchodilation,uterine relaxation).

Uses

CPR

Anaphylaxis

Rarely for other causes of bronchospasm or shock

Caution

-Cerebrovascular and heart ds.(esp.arrythmias and HTN)

-DM

-Glaucoma(open angle)

-Labour(esp.2^nd stg)

Side effect

Inc.HR,inc.BP,anxiety,sweats,tremor,headache,peripheral vasoconstriction,arrythmias,pulmonary edema,weakness,dizziness,hyperglycemia.urinary retention(esp.when prostate is enlarged)

Interaction

TCA’s

Ergotamine

Oxytocin

Risk of;

1.inc B.P&dec. H.R with beta blocker

2.Arrythmias with digoxin,quinidine and volatile liq. Anaesthetic(halothane)

Dose

CPR

1mg i/v=10ml in 10000 then flush with >=20 ml saline.If no or delayed iv access,try intraosseus route and,if this is not possible,give 2-3mg via endotracheal tube diluted to 10ml with sterile water.

Anaphylaxis

0.5mg i.m=0.5ml of 1 in 1000;repeat after 5 min if no response.(If cardiac arrest seems imminent or concern over im absorption,give 0.5mg iv slowly = 5ml of 1 in 10000 @ 1ml/min until response

Aminophylline

Methyxamthine bronchodilator; as theophylline but inc.H2O solubility (is mixed with  ethylenediamine) and dec. hypersensitivity

Use/CI/Caution/SE/Monitor/interaction

Use in severe bronchospasm can cause arrythmias- ( use cardiac monitor if giving iv)

Dose

225-450 mg bd

( or 350-700 mg bd if FORTS tab –  for smokers and others with short t1/2). If on a particular brand , ensure this is prescribed as they have different pharmacokinetics.

i/v;load 5 mg/kg (usually = 250-500 mg) over >20 min

then 0.5 mg/kg/h i/v then adjusted to keep plasma levels at 10-20 mg/l. if possible contact pharmacy for dosing advice to consider interaction , obesity and liver / heart function.

AMIODARONE

Class 3^rd antiarrythmic ; inc. refractory period of conducting system; useful as has dec. negative inotropic fx than other drugs and can give when oher ineffective/CI

Uses

Tachyarrythmias; esp paroxysomal SVT, AF, atrial flutter, nodal tachycardias, VT, and VF. Also in CPR / peri-arrest arrythmias.

CI

Inc.HR, sinoatrial heart block , san disease or severe conduction disturbance w/o pacemaker , Hx of thyroid disease/iodine.

Caution

Porphyria

DEC.K+

S/E

Acute ; N&V Dec. HR/BP ,Chronic;Rarely but seriously dec or inc T4 , interstitial lung ds. , Hepatotoxicity,conduction disturbance.Common Malaise, fatigue , photosensitive skin , corneal deposits. Less commonly;Optic neuritis , peripheral neuropathy , blood disorder , hypersensitivity.

MONITOR

TFTs & LFTS (baseline then 6 monthly). Also baseline K+ and CXR(watch for inc.SOB/alveolitis)

WARN

Avoid sunlight / use sunscreen ( inc.several months after stopping)

INTERACTION

Incs. Fx of phenytoin and digoxin.Other class 3^rd and many class 1a antiarrythmic, antipsychotic , TCAs , lithium , erythromycin , co-trimoxazole , antimalarial , nelfinavir , ritonavir , increases risk of ventricular arrythmias.Verapamil , diltiazem , and beta blocker increases risk of dec. HR and HB W+.

DOSE

Load with 200 mg tds in 1^st week , 200 mg bd in 2^nd  week , then (usually od) maintenance dose according to response(long t1/2 ;months before steady plasma concentration);i/v(extreme emergencies only)150-300 mg in 10 – 20 ml 5% glucose over >3 min (do not repeat for >15 min);ivi:5 mg/kg over 20-120 min (max 1.2 g/day).