The Dentist's Drug and Prescription Guide. Mea A. Weinberg
bleeding in the mother.
11 Q. Is ibuprofen safe in pregnant patients?
12 A. For much the same reason as aspirin, nonsteroidal antiinflammatory drugs (NSAIDs) may prolong pregnancy and should be avoided, especially in late pregnancy or after the first trimester, and can be used for 24–72 hours only.
13 Q. Which is the safest analgesic recommended for pregnant patients?
14 A. Acetaminophen alone is safe for the pregnant patient and nursing mother and is the analgesic drug of choice.
15 Q. Is epinephrine safe to administer in pregnant patients?
16 A. Yes. Epinephrine (also known as adrenaline) is a natural hormone and neurotransmitter produced by the adrenal medulla (part of the adrenal gland). It is generally considered to have no teratogenic effects when administered in dental anesthetics. It must be emphasized that since epinephrine stimulates cardiac function, when administering, careful technique (e.g., aspirate to avoid intravascular injection) and proper dosing are required (Fayans et al. 2010).
17 Q. Can acetaminophen and codeine combination be prescribed safely to a nursing patient?
18 A. On 17 August 2007, the FDA warned breastfeeding mothers who take codeine, either in combination with another analgesic or in any form of cough syrup, that babies are at increased risk for morphine overdose. Newborn babies are especially sensitive to the effects of the smallest dosages of narcotics. Codeine is metabolized to morphine and in women who are “ultra‐rapid” metabolizers of codeine, adverse effects of morphine can be seen very quickly. Being an ultra‐rapid metabolizer of codeine is due to a mutation in the gene coding for cytochrome P450 enzyme (CYP2D6) in the liver. It is relatively uncommon but does occur (www.fda.gov/drugs/postmarket‐drug‐safety‐information‐patients‐and‐providers/use‐codeine‐and‐tramadol‐products‐breastfeeding‐women‐questions‐and‐answers).
3.4 Elderly Patients
1 Q. Are dosage adjustments necessary in the elderly patient?
2 A. Yes. Volume of drug distribution, drug clearance (renal function), protein binding, and metabolism are altered in the elderly, necessitating a reduction in drug dosage. If necessary, contact the patient's physician. Additionally, there is a difference in body composition (decreased muscle mass) and function. The elderly may also have increased sensitivity to drugs because the liver metabolizes and kidneys excrete the drug less efficiently.
3 Q. Is kidney function reduced in the elderly?
4 A. Yes. Renal function progressively declines as one ages even though there could be normal serum creatinine values. Since many drugs are excreted through the kidneys, a reduction in drug dosage is necessary.
5 Q. Is liver function reduced in the elderly?
6 A. Yes. There may be a significant reduction in hepatic function, and it is important to reduce the dose of drugs metabolized by the liver.
3.5 Patients with Renal Impairment
1 Q. What are the different types of chronic kidney disease?
2 A. Renal insufficiency, which is seen in the early phase, renal failure, which occurs when the kidneys cannot function in excretion, and end‐stage renal disease (ESRD) with the nephrons losing function and uremia, which leads to malnutrition, altered drug metabolism, electrolyte imbalance, bleeding, anemia, and death.
3 Q. Does renal disease alter the response to drugs?
4 A. Yes. The use of drugs in patients with reduced kidney function (e.g., patients on dialysis) may produce toxicity because of impaired elimination from the body. Whether the dose must be reduced depends on if the drug is eliminated entirely by renal excretion or is partly metabolized. Because the kidney is the major regulator of the internal fluid environment, the physiological changes associated with renal disease have pronounced effects on the pharmacology of many drugs.Either the dose does not have to be altered or the dosing interval is increased, or the dose is reduced while maintaining the same dosing interval (this is called dose reduction and is the preferred method because it maintains more constant plasma concentrations).
5 Q. What happens to the half‐life of the drug in kidney disease?
6 A. As the plasma half‐life of drugs excreted by the kidney is prolonged in renal failure, it may take many days for the reduced dosage to achieve a therapeutic plasma concentration. Therefore, the loading dose should usually be the same size as the initial dose for a patient with normal renal function, but the maintenance dose should be reduced. Consult with the patient's physician.
7 Q. What blood values must be known before prescribing for a patient with renal impairment?
8 A. Dose recommendations are based on the severity of renal impairment which is expressed in terms of glomerular filtration rate (GFR), measured by the creatinine clearance (CrCl). CrCl, which is measured as mL/min, indicates the function of the kidneys with regard to removing creatinine, a waste product, from the blood into the urine. Both blood and urine are required to determine CrCl. CrCl is not recommended for routine evaluation of kidney function. Normal CrCl is 80–120 mL/minute.Glomerular filtration rate indicates how efficiently the kidneys are filtering wastes from the blood. GFR is used to determine the severity of kidney disease. Chronic kidney disease is defined as GFR <60 mL/min/1.73 m2 or GFR ≥60 mL/min/1.73 m2 together with kidney damage for more than three months. Serum creatinine levels are used to measure GFR (Brockmann 2010; Hassan et al. 2009).
9 Q. When should antibiotics be given to a patient undergoing dialysis?
10 A. Antibiotics should be administered after dialysis to allow for therapeutic concentrations to be maintained.
11 Q. What is the severity scale for renal disease?
12 A. Currently, according to the National Kidney Foundation, there is no uniform classification of the stages of chronic kidney disease (Table 3.18). A review of textbooks and journal articles clearly demonstrates ambiguity and overlap in the meaning of current terms.
13 Q. Can penicillin V be prescribed to patients with renal impairment?
14 A. Penicillin V is rapidly excreted through the kidneys in the urine. There is a delay in excretion in patients with impaired renal function. When GFR is <10 mL/min/1.73 m2 then the dose of penicillin V should be reduced to 250 mg every six hours.
15 Q. Which antibiotics do not require a change in dosing adjustment in chronic kidney disease?
16 A. Azithromycin, clindamycin, doxycycline (www.remedirx.com/wp‐content/uploads/2016/01/2016‐01‐M.R.‐Antibiotic‐Renal‐Dosing.pdf)
17 Q. Why is it important to know about bleeding problems in renal disease patients?
18 A. There may be a prolonged bleeding time (altered platelet aggregation) due to uremia (syndrome associated with fluid, electrolyte, and hormone imbalances and metabolic abnormalities). The platelet and hematocrit levels should be known especially if bleeding during dental treatment is anticipated. Thus, a consultation with the patient's nephrologist is required before any type of dental surgery.
19 Q. If a patient with a kidney transplant requires antibiotic prophylaxis, which antibiotic is recommended?
20 A. For antibiotic prophylaxis, no dosing adjustments are required for azithromycin or clindamycin. Amoxicillin requires dosage adjustments. If the patient is taking cyclosporine after the kidney transplant, then clarithromycin and erythromycin should not be prescribed due to the risk of cyclosporine toxicity.
21 Q. Should fluoride topical products such as PreviDent® be prescribed to a patient with renal disease?
22 A.