Pharmacology for Dentistry

398 Section 11/ Chelating Agents & Treatment of Poisoning

PRALIDOXIME

It causes reactivation of the
phosphorylated acetylcholinesterase
enzyme. After administration, it is
metabolised in liver.

Adverse effects include blurred vision,
dizziness, diplopia, headache, tachycardia,
mild weakness and nausea. In high dose it
can cause neuromuscular blockage.

It is indicated as antidote for organo-
phosphorus poisoning like malathion,
TEPP, parathion etc.

NICOTINE

Nicotine is a tertiary amine compound
composed of a pyridine and a pyrrolidine
ring. It binds selectively to acetylcholine
receptors at the autonomic ganglia in the
adrenal medulla at neuro-muscular
junction and in the brain. It exerts a
stimulating effect in the cortex and a
‘reward’ effect via the ‘pleasure system’ in
the limbic system.

Adverse effects include erythema, pru-
ritus or burning at the site of application,
headache, somnolence, dizziness, arthral-
gia, myalgia, dyspepsia, dry mouth, diar-
rhoea, sweating, BP changes, angioneurotic
edema, urticaria and dyspnea.

It is used in the treatment of nicotine
dependence and as an aid to stop smoking.

BUPROPION

The mechanism by which bupropion
acts as an aid in smoking cessation is un-
known. Bupropion weakly inhibits neu-
ronal reuptake of noradrenaline and se-
rotonin and inhibits the reuptake of

dopamine. In tissues from rat brain,

bupropion produced greater inhibition of

dopamine reuptake than noradrenaline

reuptake; however in, in vivo models,

bupropion is a stronger inhibitor of no-

radrenaline than dopamine reuptake. The

metabolites hydroxybupropion and

threohydrobupropion are pharmacologi-

cally active in vitro and in animal models

of depression and are expected to con-

tribute to the therapeutic effects of

bupropion.

Adverse effects include abdominal

pain, chest pain, facial edema, nausea, dry

mouth, constipation, diarrhoea, anorexia,

mouth ulcer, thirst, myalgia, arthralgia,

anxiety, disturbed concentration, dizziness,

nervousness, tremor, dysphoria, rhinitis,

increased cough, pharyngitis, sinusitis,

dyspnea, epistaxis, agitation, insomnia and

headache.

It is indicated in smoking cessation in

the dose of 150 to 300 mg twice daily.

TREATMENT OF POISONING

The treatment of different drug poison-

ing is discussed in individual chapters.

In this section, general treatment is

discussed.

The general principles of treatment are:

1. Support ventilation.


2. Maintain cardiovascular function.


3. Reverse hypothermia if present.


4. Treat convulsions.


5. Correct fluid, acid-base and electrolyte
   imbalance.


6. Relieve pain.


7. Good nursing care.