Pharmacology for Dentistry

318 Section 9/ Chemotherapy

portion is rapidly excreted by the kidney
mainly by tubular secretion and small
amounts appear in bile, saliva, and milk.

Adverse Effects

The penicillins are nontoxic and
remarkably safe drug. The hypersensitivity
reaction leading to anaphylaxis is only major
problem which is seen in approximately 5
to 10% of the patients taking penicillin.

The minor adverse effects include
nausea, vomiting, pain and inflammation at
the site of injection after intramuscular
administration has been reported. After
intrathecal administration (which is a
contraindication) it may lead to convulsions,
arachnoiditis and encephalopathy.

The major side effect is allergic reactions and
anaphylaxis which is characterized by skin

rash, pruritus, serum sickness like syndrome,

eosinophilia, angioneurotic edema, asthma,

haematuria, albuminuria, haemolytic

anemia, granulocytopenia and anaphylaxis.

To avoid that, a skin test using a 10,000

U of benzyl penicillin per ml is to be done

and if any local edema or wheal occurs

within 15 minutes, it is considered to be as a

positive test and in that person penicillin

should not be used.

Therapeutic Uses

Penicillin G is the drug of choice for the

following categories of infection:

• Dental infections: Penicillin G is
  effective in majority of infections
  caused by both aerobic and anaerobic
  bacteria in dentistry. It is used in acute
  suppurative pulpits, pericoronitis, oral

Table 9.3.1: Classification of penicillins.

I. Penicillinase sensitive penicillins

Benzyl penicillin (Penicillin G; sodium and potassium salt) 0.5-5 MU* IM/IV

Procaine penicillin G 0.5-1 MU IM

Benzathine penicillin G (PENIDURE) 0.6-2.4 MU IM

Phenoxymethyl penicillin (Penicillin V; KAYPEN) 250-500 mg/day

II. Penicillinase resistant penicillin

Cloxacillin (BIOCLOX) 250-500 mg 6 hourly oral/IM/slow IV

III.Broad spectrum penicillins

Ampicillin (BIOCILIN) 0.25-2 g 6 hourly, oral/IM/slow IV

Amoxycillin (NOVAMOX) 0.25-1 g/day

IV.βββββ-Lactamase Inhibitors

Clavulanic acid 125-250 mg/day oral, IV

Sulbactam 0.25-1 g/day IM/IV

V. Antipseudomonal penicillins

Carbenicillin (BIOPENCE) 1-2 g/day IM, 1-5 g IV 4-6 hourly

Piperacillin (PIPRACIL) 25-50 mg/kg IM/IV 6 hourly

Ticarcillin 200-300 mg/kg/day IV 4-6 hourly

* IU of crystalline sod. benzyl penicillin = 0.6 mg of standard preparation (1 MU = 0.6 g or 1 g = 1.6 million

units).