Why Dose Adjustment may be needed:

Increases in plasma volume and total body water which may increase the volume of distribution and thereby increase the dose
requirements that are necessary to sustain therapeutic drug levels;
Reduction in albumin levels that leads to decreased drug binding and may increase the free drug;
Steroid hormone effects on cytochrome activities which may induce CYP enzymes and lead to increased metabolism of drugs;
Increased GFR and renal excretion which may lead to increased elimination of drugs.

Common Medications

Medication	Safety in Pregnancy	Teratogenicity	Dose Adjustment Needed	Guideline
‣
Cautious, depends on type
Spontaneous abortion, low birth weight, neonatal serotonin syndrome, neonatal behavioural syndrome (withdrawal), possible abnormal neurobehavioural issues beyond neonatal period,and persistent pulmonary hypertension of the newborn	Individualized
Prefer ‣ in Pregnancy, avoid ‣

‣
Safe
No
Yes, often increased, and monitored
Test TSH if RF (universal screening not recommended),

Common Teratogenic Medication

Patients on these medications should be referred for pre-conceptual counseling and medication changes should be made as able. Medication changes may mean decreasing to lowest effective dose or changing to alternate agents.

Teratogenicity

Medication	Approach
‣	STOP
‣	Switch to ‣
‣	‣
‣ → ‣, ‣, ‣	Switch to ‣, ‣

<aside> 🌐

Pregnancy + HTN (think !Pre-eclampsia ) </aside>

Abx in Pregnancy

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