Penecillin G

Question 1

for penicillin G, describe pharmacokinetics, adverse effects and therapeutic uses (meaning, list diseases for which penicillin G is useful in treatment)

Answer 1

penicillin G is available as four salts: potassium penicillin, procaine penicillin, benzathine penicillin, sodium penicillin.

IM injection: potassium and sodium penicillin is absorbed rapidly (15 mins after injection), procaine and benzathine salts are absorbed slowly.

IV: only use potassium or sodium salts for IV admin because the other preparations are absorbed slowly.

distribution: in the absence of inflammation, penicillin G distributes well to most tissues and body fluids. but yet in the in the presence of inflammation, penicillin G entry into CSP, joints and the eyes is enhanced, enhancing treatment of infections caused by susceptible organisms.

metabolism/excretion: penicillin undergoes minimal metabolism and is eliminated by the kidneys, primarily as an unchanged drug. very short half life (30 mins). Renal impairment causes the half-life to increase dramatically and may necessitate a reduction and doses.

Question 2

for penicillin G, describe pharmacokinetics, adverse effects and therapeutic uses (meaning, list diseases for which penicillin G is useful in treatment)

adverse effects

Answer 2

allergic reactions to penicillin.
pain at sites of IM injection (resolvable)
sensory and motor dysfunction following accidental injection into a peripheral nerve
neurotoxicity (seizures, confusion, headaches) if blood levels are too high.
intra-arterial injections can cause gangrene, necrosis and sloughing of tissue.

for procaine penicillin, bizarre behavioral effects can results if there is too big of a dose given.

when large IV does of potassium penicillin are given rapidly, hyperkalemia can result, possibly causing dysrhythmias and cardiac arrest. Also can contribute to electrolyte imbalance.

Question 3

for penicillin G, describe pharmacokinetics, adverse effects, and therapeutic uses (meaning, list diseases against which penicllin G is useful)

therapeutic uses

Answer 3

penicillin G is used for:
pharyngitis caused by Streptococcus pyogenes
infectious endocarditis caused by streptococcus viridians
also the preferred drug for those few strains of Staph. aureus that do not produce penicillinase
infections caused by gram positive bacilli–gas gangrene, and anthrax
for syphilis’s treatment and prophylactics use
prophylaxis against recurrent rheumatic fever (treatment especially recommended if hx)
prophylaxis for rheumatic heart disease