Drug Fact And Comparison

2136 Pages·2007·6.41 MB·English

Drug Fact And Comparison
2007 Edition
Pocket Version

Chapter 1: Nutrients and Nutritional Agents
Recommended Dietary Allowances of Vitamins and Minerals
Recommended Dietary Allowances (RDA) are published by the Food and Nutrition
Board, National Research Council-National Academy of Sciences, as a guide for
nutritional problems and to provide standards of good nutrition for different age
groups. They are revised periodically.
The RDA values are not requirements; they are recommended daily intakes of
certain essential nutrients. Based on available scientific knowledge, they are
believed to be adequate for known nutritional needs for most healthy people under
usual environmental stresses. The recommended allowances vary for age and sex,
with extra allowances for women during pregnancy and lactation. The most
commonly used RDA values (the “reference male” and “reference female”) are those
of adults 23 to 50 years of age. With the exception of energy (kilocalories), the RDA
provide for individual requirement variations and prevent symptoms of clinical
deficiency of 97% of the population.
RDA have been established for many essential nutrients; however, present
knowledge of human nutritional needs of pantothenic acid and biotin is incomplete.
Therefore, to ensure adequate nutrient intake, obtain the recommended allowances
from as varied a selection of foods as possible. Nutritionists suggest that dietary
planning include regular intake of each of the four basic food groups:
Milk, cheese, dairy products – Minimum 2 servings/day.
Meat, poultry, fish, beans – Minimum 2 servings/day.
Vegetables, fruit – Minimum 4 servings/day.
Bread, cereal (whole-grain and enriched or fortified) – Minimum 4 servings/day.
Such a balance, in sufficient quantities will provide about 1200 kcal, enough protein,
and most of the vitamins and minerals required daily. A person may increase
nutrient and energy intake by consuming larger quantities (or more servings/day) of
the 4 basic food groups. Nutrient and energy intake may also be increased by
selecting food from the fifth group, fats-sweets-alcohol, which provides mainly
energy.
RDA quantities apply only to healthy people and are not intended to cover
therapeutic nutritional requirements in disease or other abnormal states (ie,
metabolic disorders, weight reduction, chronic disease, drug therapy). Although
certain single nutrients in larger quantities may have pharmacologic actions, these
are unrelated to nutritional functions. There is no convincing evidence that
consuming excessive quantities of single nutrients will cure or prevent nonnutritional
diseases.
The “official” listings of United States Recommended Daily Allowances (US-RDAs)
should not be confused with the RDA values. US-RDA are derived from the 1968
RDA and serve as legal standards for nutritional labeling of food and dietary food
and dietary supplement products controlled by the FDA. Generally, they represent
the higher value of the male or female RDA and are grouped into only 3 age
brackets plus 1 category for pregnant or lactating women. Prior to 1972, these
allowances were erroneously listed as minimum daily requirements (MDR). A
second fallacy perpetuated by US-RDA labeling of foods is the implication that a
food is defective if it does not contain all the officially established nutrients in their
full US-RDA quantities. No individual food is nutritionally complete, but several foods
together should complement each other to provide maximal nutrient balance and to
minimize naturally occurring toxic principles consumed from any individual foodstuff.
The RDA for adult males and adult females are included in each individual vitamin
monograph. The table on the following page presents the listing of vitamin and
mineral RDA values for all age groups as published in Recommended Dietary
Allowances, 10th Edition, National Academy of Sciences, Washington, DC, 1989.
Dietary Reference Intakes (DRIs) refer to nutrient intake values estimated to be
adequate for 50% of age- and gender-specific groups. As seen in the table below,
DRIs are comprised of RDAs in bold type and Adequate Intakes (AIs) in ordinary
type followed by asterisk (*). These values may be used as goals for individual
intake. RDAs are estimated to meet the needs of most individuals (97% to 98%). For
healthy breast-fed infants, the AI represents mean intake. For all other life-stage
groups, the AI is believed to cover the needs of all individuals, but a lack of data or
uncertainty in the data prevent specifying with confidence with percentage of
individuals covered by this intake.
Vitamins
Vitamin C (Ascorbic Acid)
ASCORBIC ACID
Tablets: 25, 50, 100, 250, 500, and 1,000 Various, One A Day Extras
mg (otc) Vitamin C (Miles)
Tablets, chewable: 60, 100, 250, and 500 Various
mg (otc)
Tablets and caplets, timed-release: 500, Various
1,000, and 1,500 mg (otc)
Caplets: 500 mg (otc) SunKist Vitamin C (Ciba)
Capsules, timed-release: 500 mg (otc) Various, Ascorbicap (ICN),
Cevi-Bid (Geriatric)
Lozenges: 60 mg (otc) N'ice Vitamin C Drops
(SmithKline Beecham Consumer)
Crystals: 4 g/teaspoonful (otc) Vita-C (Freeda)
Powder: 4 g/teaspoonful (otc) Dull-C (Freeda)
Liquid: 35 mg/0.6 mL (otc) Ce-Vi-Sol (Mead Johnson
Nutritional)
Solution: 100 mg/mL (otc) Cecon (Abbott)
Syrup: 500 mg/5 mL (otc) Various
Injection: 250 and 500 mg/mL (Rx) Various
CALCIUM ASCORBATE
Tablets: 610 mg (equiv. to 500 mg ascorbic Various
acid) (otc)
Powder: 1 g (equiv. to 826 mg ascorbic Various
acid)/¼ teaspoonful (otc)
SODIUM ASCORBATE
Tablets: 585 mg (equiv. to 500 mg ascorbic Various
acid) (otc)
Crystals: 1,020 mg (equiv. to 900 mg Various
ascorbic acid)/¼ teaspoonful (otc)
Injection: 250 mg/mL (equiv. to 222 mg/mL Various
ascorbic acid) (Rx)
562.5 mg/mL (equiv. to 500 mg/mL Cenolate (Abbott)
ascorbic acid) (Rx)
Indications
Prevention and treatment of scurvy. Parenteral administration is desirable in an
acute deficiency or when absorption of oral ascorbic acid is uncertain.
Unlabeled uses: Vitamin C (at least 2 g/day) may be used as a urinary acidifier in
conjunction with methenamine therapy.
Vitamin C in doses of at least 150 mg has been used to control idiopathic
methemoglobinemia (less effective than methylene blue).

Administration and Dosage
Parenteral: Administer IV, IM, or subcutaneously. Avoid too rapid IV injection.
Absorption and utilization are somewhat more efficient with the IM route, which is
usually preferred.
Infants: Average daily protective requirement is 30 mg. The usual curative dose is
100 to 300 mg daily, continued as long as clinical symptoms persist or until
saturation, as indicated by excretion tests, has been attained.
Premature infants: May require 75 to 100 mg/day.
Adults: The average protective dose is 70 to 150 mg/day. For scurvy, 300 mg to 1 g
daily is recommended. However, up to 6 g/day has been administered parenterally
to normal adults without evidence of toxicity.
Enhanced wound healing – Doses of 300 to 500 mg daily for 7 to 10 days both
preoperatively and postoperatively are adequate, although considerably larger
amounts have been recommended.
Burns – For severe burns, daily doses of 1 to 2 g are recommended.
In other conditions in which the need for vitamin C is increased, 3 to 5 times the daily
optimum allowances appears adequate.
Actions
Pharmacology: Vitamin C, a water-soluble vitamin, is an essential vitamin in man;
however, its exact biological functions are not fully understood. It is essential for the
formation and the maintenance of intercellular ground substance and collagen, for
catecholamine biosynthesis, for synthesis of carnitine and steroids, for conversion of
folic acid to folinic acid and for tyrosine metabolism.
The deficiency state scurvy is characterized by degenerative changes in the
capillaries, bone, and connective tissues. Mild vitamin C deficiency symptoms may
include faulty bone and tooth development, gingivitis, bleeding gums, and loosened
teeth.
Absorption of dietary ascorbate from the intestines is nearly complete. Vitamin C is
readily available in citrus fruit, tomatoes, potatoes, and leafy vegetables.
Warnings
Excessive vitamin C doses: Diabetics, patients prone to recurrent renal calculi, those
undergoing stool occult blood tests and those on sodium restricted diets or
anticoagulant therapy should not take excessive doses of vitamin C over an
extended time period.
Pregnancy: Category C. Do not administer ascorbic acid to pregnant women in
excess of the amount needed for treatment. The possibility of the fetus adapting to
high levels of the vitamin could result in a scorbutic condition after birth when the
intake drops to normal levels. This action is controversial.
Lactation:Ascorbic acid is excreted in breast milk.
Drug Interactions
Contraceptives (oral) and estrogens: Ascorbic acid increases serum levels of
estrogen and estrogen contained in oral contraceptives, possibly resulting in adverse
reactions.
Warfarin:The anticoagulant action of warfarin may be reduced.
Drug/Lab test interactions: Large doses (more than 500 mg) of vitamin C may cause
false-negative urine glucose determinations.
No exogenous vitamin C should be ingested for 48 to 72 hours before
amine-dependent stool occult blood tests are conducted because possible
false-negative results may occur.
Adverse Reactions
Large doses may cause diarrhea and precipitation of cystine, oxalate, or urate renal
stones if the urine becomes acidic during therapy.
Transient mild soreness may occur at the site of IM or subcutaneous injection. Too
rapid IV administration may cause temporary faintness or dizziness.

Niacin
Tablets: 50, 100, 250, and 500 mg (otca) Various
Tablets, timed-release: 250 and 500 mg (otca) Various
Tablets, sustained-release: 500 mg (otca) Various
Tablets, controlled-release: 250, 500, and 750 mg Slo-Niacin
(otca/sf) (Upsher-Smith)
Capsules, extended-release: 250 and 400 mg (otca) Various
Capsules, timed-release: 250 and 500 mg (otca) Various
Various
Capsules, sustained-release: 125 and 500 mg
a
(otc )
a
Some products may be available Rx, according to distributor discretion. Most of
these products are marketed as nutritional supplements.
Indications
Dietary supplement: For the treatment of niacin deficiency.
Administration and Dosage
To reduce flushing, begin therapy by slowly increasing the dose.
Recommended dietary allowances (RDAs): Adult men, 15 to 20 mg; adult women,
13 to 15 mg. Niacin is recommended at 6.6 mg per 1,000 Kcal intake.
The following prescribing information pertains primarily to therapeutic uses of niacin
in doses exceeding basic nutritional intake (RDA levels).
Hyperlipidemia: The following dosages are from the National Cholesterol Education
Program (NCEP) Expert Panel III guidelines:
Crystalline nicotinic acid – Usual daily dose is 1.5 to 3 g (maximum daily dose 4.5 g).
Sustained-release nicotinic acid – Usual daily dose is 1 to 2 g (maximum daily dose
2 g).
Sustained-release: Do not substitute sustained-release (modified-release,
timed-release) nicotinic acid preparations for equivalent doses of immediate-release
(crystalline) nicotinic acid.
Actions
Pharmacology: Niacin, vitamin B , is the common name for nicotinic acid and
3
niacinamide (nicotinamide). Nicotinic acid is present in the body as its active form,
nicotinamide (niacinamide).
Although nicotinic acid and nicotinamide function identically as vitamins, their
pharmacologic effects differ. In large doses (up to 6 g/day), nicotinic acid is effective
in reducing serum lipids (low-density lipoprotein [LDL], high-density lipoprotein
[HDL], triglycerides, and lipoprotein A. Nicotinic acid produces vasodilation and
increased blood flow due to histamine release. Nicotinamide does not affect blood
lipid levels or the cardiovascular system.
Deficiency – Pellagra is a state of niacin deficiency characterized by dermatitis,
diarrhea, and dementia (manifestations of mucous membranes, GI system, and
CNS). In severe cases, confusion, delusions, disorientation, and hallucinations may
occur.
Pharmacokinetics: Niacin is rapidly absorbed from the GI tract; peak serum
concentrations usually occur within 45 minutes. The plasma elimination half-life is
approximately 45 minutes. Approximately one third of an oral dose is excreted
unchanged in the urine.
Contraindications
Hepatic dysfunction; active peptic ulcer; arterial bleeding; hypersensitivity to niacin or
any ingredient.
Warnings
Alcohol: Use with caution in patients who consume substantial quantities of alcohol
or have a history of liver disease.
Schizophrenia: There is no evidence to support the use of nicotinic acid in the
treatment of schizophrenia as part of what is referred to as “orthomolecular
psychiatry.”
Heart disease: People with heart disease, particularly those who have recurrent
chest pain (angina) or who recently suffered a heart attack, should take niacin only
under the supervision of a health care provider.
Pregnancy: Category A. (Category C if used in doses above the RDA). It is not
known whether nicotinic acid at doses typically used for lipid disorders can cause
fetal harm. If a woman receiving nicotinic acid for primary hypercholesterolemia
(types IIa or IIb) becomes pregnant, discontinue the drug. If a woman being treated
with nicotinic acid for hypertriglyceridemia (types IV or V) becomes pregnant, assess
the benefits and risks of continued drug therapy on an individual basis.
Lactation: Niacin is actively excreted in breast milk.
Children: Safety and efficacy in children have not been established in doses that
exceed the RDA.
Precautions
Monitoring: Frequently monitor liver function, blood glucose, and uric acid.
Diabetes: Observe diabetic or borderline diabetic patients closely for decreased
glucose tolerance. Avoid doses greater than 3 g/day.
Gout: Elevated uric acid levels have occurred.
Flushing: Flushing generally begins 20 minutes after ingestion and lasts 30 to 60
minutes. Flushing will usually subside after 3 to 6 weeks of continued therapy. The
flush response can be attenuated by slowly increasing the niacin dose (100 mg 3
times/day each week), administering with food or milk, administering either a
prostaglandin inhibitor, (eg, aspirin 325 mg) 60 minutes prior to niacin administration,
or administering sustained-release niacin preparations.
Special risk: Closely observe patients with gallbladder disease, a history of jaundice,
glaucoma, hepatobiliary disease, liver disease, peptic ulcer, or arterial bleeding. Use
caution when nicotinic acid is used in patients with unstable angina or in the acute
phase of MI, particularly when such patients are also receiving vasoactive drugs
such as nitrates, calcium channel blockers, or adrenergic blocking agents.
Drug Interactions
HMG-CoA reductase inhibitors: Coadministration of niacin and HMG-CoA reductase
inhibitors (eg, lovastatin) may result in myopathy and rhabdomyolysis.
Adverse Reactions
Dermatologic: Acanthosis nigricans, dry skin, itching, pruritus, rash, sensation of
warmth, severe generalized flushing, tingling.
GI: Abdominal pain, activation of peptic ulcer, diarrhea, dyspepsia, nausea, vomiting.
The frequency of GI complaints is higher in users of extended-release niacin. GI
distress can be minimized by dividing the total daily dose into a twice daily or 3 times
daily dosage regimen.
Hepatic: Nicotinic acid hepatotoxicity (including cholestatic jaundice) has occurred.
Cases of severe hepatic toxicity, including fulminant hepatic necrosis, have occurred
in patients who have substituted sustained-release nicotinic acid products for
immediate-release nicotinic acid at equivalent doses. Monitor ALT prior to treatment,
every 6 to 12 weeks during the first year, and periodically thereafter (approximately
6-month intervals).
Lab test abnormalities: Abnormalities of hepatic function tests, decreased glucose
tolerance, gout, hyperuricemia.
Miscellaneous: Atrial fibrillation and other cardiac arrhythmias, cystoid macular
edema, decreased glucose tolerance, hypotension, orthostasis, toxic amblyopia,
transient headache.
Niacinamide
Tablets: 100 and 500 mg (otca) Various
a
Some products may be available Rx, according to distributor discretion.
Indications
Pellagra: Prophylaxis and treatment of pellagra.
Administration and Dosage
100 to 500 mg/day.

Actions
Pharmacology: Niacinamide is synonymous with nicotinamide, 3-pyridine
carboxamide, and nicotinic acid amide. Niacinamide is the amide of nicotinic acid
(niacin, vitamin B ). Although nicotinic acid and nicotinamide function identically as
3
vitamins, their pharmacologic effects differ. Nicotinamide does not have the
hypolipidemic or vasodilating effects characteristic of niacin (nicotinic acid).
Adverse Reactions
Liver dysfunction in high doses.

Vitamin B
12
Tablets: 100, 500, and 1,000 mcg (otc) Various