McKenna's Pharmacology for Nursing, 2e

906

P A R T 1 1  Drugs acting on the gastrointestinal system

status of pregnancy or breastfeeding due to possible effects on the fetus or newborn. ■ ■ Perform a physical examination to establish baseline data before beginning therapy, determine the effectiveness of the therapy, and evaluate for any potential adverse effects associated with drug therapy. ■ ■ Inspect the abdomen. Auscultate bowel sounds to ensure GI motility. ■ ■ Assess mucous membrane status to evaluate potential problems with absorption and hydration. ■ ■ Monitor laboratory test results, including serum electrolyte levels and renal function tests, to ■ ■ Administer the drug apart from any other oral medications approximately 1 hour before or 2 hours after to ensure adequate absorption of the other medications. ■ ■ Have the person chew tablets thoroughly and follow with water to ensure that therapeutic levels reach the stomach to decrease acid. ■ ■ Obtain specimens for periodic monitoring of serum electrolytes to evaluate drug effects. ■ ■ Assess the person for any signs of acid–base or electrolyte imbalance to ensure early detection and prompt intervention. ■ ■ Monitor the person for diarrhoea or constipation to institute a bowel program before severe effects occur. ■ ■ Monitor the person’s nutritional status if diarrhoea is severe or constipation leads to decreased food intake to ensure adequate fluid and nutritional intake to promote healing and GI stability. ■ ■ Offer support and encouragement to help the person cope with the disease and the drug regimen. ■ ■ Provide thorough teaching, including the drug name and prescribed dosage; schedule for administration; signs and symptoms of adverse effects and measures to minimise or prevent them; warning signs that may indicate possible problems and the need to notify the healthcare provider immediately; the importance of maintaining fluid and nutritional intake if diarrhoea or constipation occurs; possible bowel training programs to deal with constipation or diarrhoea if severe; cautions related to prolonged chronic use of drug and increased risk for acid rebound; the importance of checking with the healthcare provider before using any OTC medications; differences associated with the various OTC antacid formulations; and monitor for adverse effects of the drug and potential alterations in excretion that may necessitate dose adjustment. Implementation with rationale

the need for periodic monitoring and evaluation to enhance knowledge about drug therapy and to promote compliance.

Evaluation

■ ■ Monitor response to the drug (relief of GI symptoms caused by hyperacidity).

■■ Antacids are used to chemically react with and neutralise acid in the stomach. They can provide rapid relief from increased acid levels. They are known to cause GI alterations such as diarrhoea or constipation and can alter the absorption of many drugs. ■■ Acid rebound occurs when the stomach produces more gastrin and more acid in response to lowered acid levels in the stomach, which commonly occurs with the use of antacids. Balancing the reduction of the stomach acid without increasing acid production is a clinical challenge. P roton pump inhibitors Proton pump inhibitors (Table 57.1) suppress the secre- tion of hydrochloric acid into the lumen of the stomach. Five proton pump inhibitors are presently available: omeprazole ( Losec ), esomeprazole ( Nexium ), lansopra- zole ( Zopral, Zoton ), pantoprazole ( Ozpan, Pantoloc ) and rabeprazole ( Pariet, Prabez ). Therapeutic actions and indications The gastric acid pump or proton pump inhibitors suppress gastric acid secretion by specifically inhibit- ing the hydrogen–potassium adenosine triphosphatase (H + , K + -ATPase) enzyme system on the secretory surface of the gastric parietal cells. This action blocks the final step of acid production, lowering the acid levels in the stomach (see Figure 57.1). They are recommended for the short-term treatment of active duodenal ulcers, GORD, erosive oesophagitis and benign active gastric ulcer; for the long-term treatment of pathological hyper- secretory conditions; as maintenance therapy for healing ■ ■ Monitor for adverse effects (GI effects, imbalances in serum electrolytes and acid–base status). ■ ■ Evaluate the effectiveness of the teaching plan (person can name the drug and dosage, as well as describe adverse effects to watch for, specific measures to avoid them and measures to take to increase the effectiveness of the drug). ■ ■ Monitor the effectiveness of comfort measures and compliance with the regimen. KEY POINTS