NR 566 Week 7 Study Guide
Chapter 48: Women as Patients
Pharmacokinetic gender differences between men and women
These three medications have shown differences that are clearly significant between men and women
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NR 566 Week 7 Study Guide
Chapter 48: Women as Patients
Pharmacokinetic gender differences between men and women
These three medications have shown differences that are clearly significant between men and women
Propranolol (Inderal): early drug that showed a clear gender difference in metabolism (clearance)
o PO doses: significantly higher (63%) rate of clearance in men than women
o IV doses do not do this: indicates hepatic first pass metabolism
o Women: show a significantly greater clinical response to PO doses
Verapamil (Isoptin, Calan): PO clears more quickly in men than women based on CYP3A4
o Higher absolute bioavailability in women causes greater pharmacodynamic effects on BP and HR in
women
Erythromycin: more effective in women
o More rapidly cleared in women than men r/t CYP 3A4
Pharmacokinetic
Parameter Sex-Based Difference
Absorption and
bioavailability
• Gastric emptying time is slower in females, mainly related to the effects of
estrogen. Drugs absorbed in the stomach will have longer exposure to
absorption sites.
• Gastric levels of alcohol dehydrogenase are lower in females. Plasma
concentrations are greater in females than males after ingestion of similar
amounts of alcohol.
• Gastric acid secretion, pH, osmolality, electrolyte concentrations, and levels
of bile acids and proteins do not vary significantly between sexes.
Distribution • Females have lower body weights and BMI than males.
• Females have a higher proportion of body fat. Lipophilic drugs are more
readily absorbed and have relatively greater volumes of distribution than
hydrophilic drugs.
• Plasma volume is lower in females. Drugs with high volumes of distribution
will be more concentrated in the plasma of females.
• Organ blood flow is lower in females.
• Estrogen is distributed attached to a serum-binding globulin. Exogenous
estrogens increase levels of many serum-binding globulins such as
corticosteroid-binding globulin and thyroxine-binding globulin resulting in
less free drug.
Metabolism • Studies have been inconsistent in showing differences in CYP450 substrates;
the general trend is toward high rates of metabolism for CYP450 3A4
substrates and lower rates for 1A2 and 2D6 substrates.
• Females have lower levels of p-glycoprotein and higher rates of drug
clearance for drugs that are substrates of p-glycoprotein.
Excretion • Gender differences in rates of renal excretion of most drugs are probably
more related to simple weight differences.
Renal clearance of drugs that are not actively secreted or reabsorbed is
dependent on the glomerular filtration rate, which is directly proportional to
weight and consequently higher (on average) in men.
Pharmacokinetic
Parameter Sex-Based Difference
• Drugs that are actively secreted by the kidney may show gender differences,
but further study is required to demonstrate this difference.
Recommended Calcium and Vitamin D Intake for Adolescents and Adults
Adolescents
o 1,300 mg of calcium daily is recommended for females aged 9 through 18 years,
drinking three cups of low-fat or skim milk & consuming 8 ounces of low-fat yogurt.
If unable to meet the recommended daily amount of calcium through diet alone, calcium
carbonate (Tums, Caltrate, or Viactiv) with food to maximize absorption.
o vitamin D is required for optimal calcium absorption
a daily multivitamin that includes at least 400 IU vitamin D should also be taken
Adults
o 19-50 years old: 1,000 mg/day
o 51-70 y/o: 1,000 mg/day
o 71+: 1,200 mg/day
Non-Pharmaceutical Treatment of Symptoms Associated with Menopause
Many options for managing menopausal symptoms are available exercise, relaxation techniques, massage
therapy, acupuncture, herbs, or pharmaceuticals (such as HRT)
Some women unable or choose not to take HRT and have turned to phytoestrogenssubstances with
estrogen-like properties found in
o certain herbs: ginseng, black cohosh, dong quai, fenugreek, and licorice
o certain foods—especially carrots, yams, and soy products—varying efficacy
Nutritional supplements for a diet rich in calcium and vitamins E, D, and B complex.
Menopausal women should avoid foods such as caffeine, alcohol, and spicy foods that can trigger
vasomotor symptoms
Table 48-3: Alternative Therapies for Menopause Symptoms
o Hot flashes: pharmaceuticals
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