McKenna's Pharmacology for Nursing, 2e

820 P A R T 9  Drugs acting on the renal system C onditions affecting the urinary tract and bladder are common problems. These conditions include acute urinary tract infections (UTIs), bladder spasms, bladder pain and benign prostatic hyperplasia (BPH). Females, with shorter urethras, are particularly vulnerable to repeated urinary tract, bladder and even kidney infections. Children also may have frequent urinary tract problems. People with indwelling catheters or intermittent catheterisations often develop bladder infections or cystitis , which can result from bacteria introduced into the bladder by these devices. Blockage anywhere in the urinary tract can lead to backflow problems and the spread of bladder infections into the kidney ( pyelonephritis ). The signs and symptoms of a UTI are uncomfortable and include urinary frequency , urgency , burning on urination (associated with cystitis), and chills, fever, flank pain and tenderness (associated with acute pyelonephritis). To treat these infections, cli- nicians use specific urinary tract anti-infectives, which include antibiotics, as well as specific agents that reach antibacterial levels only in the kidney and bladder and are thought to sterilise the urinary tract. Drugs also are available to block spasms of the urinary tract muscles, decrease urinary tract pain, protect the cells of the bladder from irritation, and treat enlargement of the prostate gland in men. Table 52.1 summarises urinary tract problems and the drugs of choice to treat them. Box 52.1 highlights important Urinary tract agents CHILDREN Children may develop urinary tract infections (UTIs), including cystitis, and need to be treated with a urinary tract anti-infective. Some children, because of congenital problems or indwelling catheters, require other urinary tract agents such as urinary tract analgesics or antispasmodics.The older anti‑infectives—such as nitrofurantoin and hexamine hippurate—have established paediatric guidelines. A child with repeated urinary tract infections should be evaluated for potential sexual abuse. Children need to be instructed in proper hygiene and should not be given bubble baths if urinary tract infections occur.They should be encouraged to avoid the alkaline ash juices such as orange or grapefruit juice and urged to drink lots of water. If an antispasmodic is needed, oxybutynin is indicated for children older than 5 years of age. ADULTS Adults need to be cautioned about the various measures that can be used to decrease the likelihood of urinary tract infections.They should be encouraged to drink plenty of fluids to maintain bladder health. If they are taking an anticholinergic to block spasm, adults need to be advised of other precautions to take when the parasympathetic system is blocked. BOX 52.1

■■ TABLE 52.1

Urinary tract problem

Drugs of choice

Infection

Urinary tract anti-infectives: hexamine hippurate, nitrofurantoin, norfloxacin Antispasmodics: oxybutynin, tolterodine Bladder protectant for interstitial cystitis: pentosan Alpha-adrenergic blockers: alfuzosin, tamsulosin, terazosin Testosterone inhibitor: finasteride, dutasteride

Spasm

Pain

Benign

prostatic hyperplasia

considerations related to urinary tract drugs based on the person’s age.

URINARY TRACT ANTI-INFECTIVES Urinary tract anti-infectives (Table 52.2) are of two types. One type comprises the antibiotics, which are particularly effective against the gram-negative bacteria that cause most UTIs. The antibiotics used specifically to treat UTIs include norfloxacin ( Noroxin, Roxin ) and nitrofurantoin ( Macrodantin ). Ciprofloxacin ( Cifran ) and sulfamethoxazole and trimethoprim ( Bactrim, Resprim ) are also used frequently to treat UTIs but are

Drug therapy across the lifespan

Adult men being treated for benign prostatic hyperplasia need to be aware of the possibility of decreased sexual function, as well as fatigue, lethargy and the potential for dizziness, which could interfere with

working or activities of daily living. PREGNANCY AND BREASTFEEDING

The use of urinary tract agents during pregnancy should be approached with caution. Women who are breastfeeding should use these agents with caution because of the potential for adverse effects on the baby, or they should find another method of feeding the baby. OLDER ADULTS Older adults often have conditions that are treated with the urinary tract agents.They are also more likely to have renal or hepatic impairment, which requires caution in the use of these drugs. Older adults should be started on the lowest possible dose of the drug, and it should be titrated slowly based on response. Special precautions to monitor cardiac function, intraocular pressure, blood pressure and bladder emptying need to be taken when using alpha-adrenergic blockers with these people. Older people may have a difficult time maintaining fluid intake and might benefit from extra encouragement to drink fluids, including cranberry juice, and to avoid alkaline ash drinks.