Module232025

07/05/2025

Pregnancy – AD & E changes

Absorption, distribution and excretion changes in pregnancy – all can affect pharmacokinetics and impact dosing recommendations

For a more detailed review, see Ref #3

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Pregnancy – (some) hepatic metabolic changes

Pregnancy Effect

Enzyme

Trimester(s)

Examples

Cyp 1A2 Cyp 2A6 Cyp 2C9 Cyp 2C19 Cyp 2D6

I-III

Caffeine, paracetamol, theophylline

III III

Nicotine, sodium valproate

ACEIs, NSAIDs, phenytoin, warfarin

II-III

Citalopram, proguanil

I-III

Methadone, metoprolol, TCAs, SSRIs, venlafaxine Carbamazepine, nifedipine, (some) protease inhibitors

Cyp 3A4

I-III

Glucuronosyl transferases N-acetyl transferase

I-III

Lamotrigine, morphine

I

Isoniazid, hydralazine

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