Drug Excretion in Non-Renal Routes

1. Drug Excretion

2. Drug excretion in Milk.
• Most of the drugs consumed during lactation
are found to be detected in breast milk
• However ,quantitatively insignificant from
mothers point of view but often sufficient
enough to cause harmful effect on suckling
infant, because of inherent toxicity of the
drug.
• The passage of drug to breast milk is by
diffusion

3. Excretion in milk continued…..
• Drugs which are highly protein bound are less
secreted in milk.
• Milk is slightly Acidic
• Hence basic drugs tend to get concentrated more
in milk than acidic drugs.
• Most drugs are safe, some drugs may suppress
lactation or alter the taste.
• Any drugs to be taken should be done,
immediately after breast feeding or 4 hours
before breast feeding-ensuring that drug gets
cleared.

4. Drugs contraindicated during
lactation.
• Most of Anti-cancer drugs
• All radio-pharmaceuticals, including radio active
isotopes
• Anti-thyroid drugs including radio active iodine.
• Antimicrobial drugs like
1. Tetracyclines –bone and teeth malformations.
2. Chloramphenicol-grey baby syndrome.
3. Sulfonamides-kernicterus.
4. Quinolones- joint and cartilage damage.
5. INH- Hepatotoxicity.

5. Drugs contraindicated during lactation
• Hormones
1. Glucocorticoids –supression of body growth
and HPA axis.
2. Contraceptives –supress lactation.
• CNS depressants/sedative hypnotics-induces
sedation, impaired intellectual development,
delayed milestones
• Opoids analgesic –respiratory depression
• Lithium-cardiac arrythmia and supression of
thyroid function.
• Anthracene purgatives-induce abdomonal
cramps
• Anti psychotic

6. Drugs contraindicated during lactation
• Ephedrine and theophylline - CNS stimulants,
makes child irritable.
• Aspirin – causes Reye s syndrome.
• Among antimicrobials ,penicillin and
cephalosporins are virtually harmless thogh
safe produce abdominal distension and
diarrhoea.
• Bromocriptine and other ergot alkaloids used
deliberately to supress lactation.

7. Drugs excretion through body
integuments like skin ,hair ,nails.
• Some drugs may get deposited in body
integuments.
• When superficial layers are insensibly lost
,which result in drug excretion.
• Presence of drugs in the above is of
importance in arsenic or mercury poisoning
• Quantitatively insignificant but has medico
legal siginificance.

8. Pharmacokinetic convention/measures
/parameters.
1. Bioavaliability
2. Volume of distribution
3. Half-life
4. Clearance rate

9. Half life
• Is defined as the time required for 50% decline
in either concentration or effect of drug.
• Depending upon the ccriteria considered
there are 4 types
1. Plasma half life
2. Biological/elimination
3. Pharmacological
4. physical

10. 1. Plasma half life
• Time required for 50% reduction in plasma
concentration of the drug
• Once peak concentration is achieved, there is
progressive decrease in plasma concentration
of drug
• This is due to drug distribution and disposal
• Plasma concentration decrese in two distinct
phase
• Initial phase of rapid decline-due to
distribution
• Subsequent phase of steady decline –disposal.