A nurse is reinforcing teaching with a client who has schizophrenia and a new prescription for haloperidol. The nurse should instruct the client to avoid taking which of the following medications?

A. Aspirate before injecting the medication. Aspirating before injecting heparin is not recommended because it can cause tissue trauma and increase the risk of hematoma formation. Heparin is administered into the subcutaneous tissue, which has fewer blood vessels than intramuscular tissue, making aspiration unnecessary. Aspiration can also lead to bruising and discomfort, which should be minimized when administering anticoagulants.

B. Use a 25-gauge, 1/2-inch needle to administer the medication. Heparin should be administered using a small-gauge (25- to 27-gauge) needle with a length of 1/2 to 5/8 inch to reduce tissue trauma and minimize the risk of bleeding. The small needle size helps ensure that the medication is delivered into the subcutaneous tissue rather than deeper layers. Proper needle selection is important to prevent bruising and irritation, which are common concerns when administering anticoagulants.

C. Administer the medication within 2 cm (1 in) of the umbilicus. Heparin should not be injected near the umbilicus because this area has a higher density of blood vessels and an increased risk of bruising. The preferred injection sites are the abdomen (at least 5 cm or 2 inches away from the umbilicus), the upper outer thigh, or the outer upper arm. Injecting in these areas ensures proper absorption while minimizing complications such as hematoma formation.

D. Massage the site after injecting the medication. Massaging the injection site after administering heparin is contraindicated because it can lead to increased bruising, tissue irritation, and the potential for excessive bleeding. Instead of massaging, gentle pressure can be applied with a gauze pad if necessary to control minor bleeding. Clients should be advised to avoid rubbing or applying unnecessary pressure to the injection site to reduce the risk of local complications.

A. Drowsiness. Dimenhydrinate is an antihistamine that works by blocking histamine and acetylcholine receptors in the brain to prevent nausea and vomiting. A common adverse effect is drowsiness due to its sedative properties, which can impair alertness and coordination. Clients should be advised to avoid activities requiring mental alertness, such as driving, until they understand how the medication affects them.

B. Hypertension. Dimenhydrinate does not typically cause hypertension. Instead, it may lead to mild hypotension due to its sedative and anticholinergic effects. Clients with pre-existing hypertension should still monitor their blood pressure, but significant increases are uncommon.

C. Polyuria. Increased urination is not associated with dimenhydrinate use. Antihistamines, including dimenhydrinate, have anticholinergic properties, which can lead to urinary retention rather than increased urine output. Clients experiencing difficulty urinating should report this to their healthcare provider.

D. Dependent edema. Dimenhydrinate does not cause fluid retention or edema. Medications that contribute to edema typically involve hormonal, cardiovascular, or kidney-related effects, which are not mechanisms of dimenhydrinate. If a client develops unexplained edema, other underlying conditions should be investigated.