Contraindications

Each medication administration route has unique contraindications, and the healthcare team members need to recognize them. An oral medication route is contraindicated for patients who cannot tolerate oral drugs, such as those who have altered mental status or have nausea or vomiting that hinder them from safely ingesting the drug orally. A rectal route is contraindicated in patients with active rectal bleeding or diarrhea or after a recent rectal or bowel surgery. An intramuscular route is contraindicated in an active infection or inflammation at the site of drug administration, myopathies, muscular atrophy, thrombocytopenia, or coagulopathy.

A subcutaneous route of medication is contraindicated in an actively infectious or inflamed site. Doses that require to be injected more than 1.5 mL at once should be avoided. Subcutaneous injection volumes larger than 2 mL are associated with adverse effects, including pain and leakage at the injection site.  An intranasal medication is contraindicated in patients with nasal trauma, anatomic obstruction, the presence of a foreign body, or copious mucous or bleeding. Similarly, an inhaled medication is contraindicated in patients with airflow obstruction.

Equipment

The equipment required depends on the route chosen for medication administration. In general, equipment needed for the parenteral route may include gauze, dry cotton swab, nitrile gloves, chlorhexidine or alcohol-based antiseptic agent, tourniquet, appropriately gauged intravenous catheter, syringe, normal saline flush, and a bandage. A local anesthetic agent may be used for larger cannulas or to minimize discomfort in some patients, such as pediatric patients. A lubricant can be utilized in the rectal or vaginal administration of medication to reduce friction and discomfort.\

Preparation

The “five rights” are emphasized for the preparation of medication administration: right patient, right drug, right dose, right site, and right timing. It is essential to explain to patients how the medication will be administered, obtain consent for procedures when indicated (e.g., central venous catheter), and help prepare patients before they receive their medication. The site of application of the medication should be chosen based on its adequacy and indications. The label on the medication should be checked for its name, dose, and approved usage route.

Technique

Techniques involved in each route of medication administration are different, and some of the important points are summarized as follows:

Intravenous Route

A tourniquet may be used over the site intended for the intravenous medication to make the vein more visible and easier to access. However, when used, the tourniquet must be removed before injecting the medication to prevent extravasation. In central lines or peripherally inserted central catheter (PICC) lines for medication administration, ultrasound guidance is often used.

Intramuscular Route

Intramuscular injection should be done at a perpendicular angle as it has been shown to be the most effective method for patient comfort, safety, and medication efficacy. Skin traction and deep pressure on the muscle can help decrease patients’ pain and discomfort.

Subcutaneous Route

A subcutaneous route requires minimal skills and training, and patients can often quickly learn to inject medications into themselves. It is recommended that instead of using the same site, patients rotate the sites of injection to avoid complications such as lipohypertrophy that can cause incomplete medication absorption.  The injection is usually at an angle if using a needle/syringe or at a perpendicular angle if using an injector pen.

Rectal Route

It is recommended to have the patient lie on the left side with the right knee bent towards the chest as this position enables the medication to flow into the rectum and subsequently to the sigmoid colon by gravity. Separate the buttocks with the non-dominant gloved hand and gently insert the medicine 2 to 4 cm into the rectum using the dominant hand’s gloved index finger. A lubricant may be used for the patient’s comfort. If administering a laxative suppository, the patient will need a bedpan or commode or be placed close to the toilet. It is recommended that the patient remains on the side for 5 to 10 minutes unless otherwise specified by the medication’s directions.

Vaginal Route

Position the patient onto their back with legs bent and feet resting flat on the bed. A lubricant can be used to reduce friction against the vaginal mucosa as the medication is administered. Gently separate labial folds with the non-dominant gloved hand while with the dominant gloved index finger, insert the lubricated suppository to about 8-10 cm along the posterior vaginal wall.

Inhaled Route

Each inhaler has instructions from the manufacturer. For metered-dose inhalers, some of the essential techniques include: shaking the inhaler vigorously for a few seconds before each puff; inhaling through the mouth, not the nose when breathing in the medication; keeping the tongue under the mouthpiece to avoid blocking the mouthpiece; taking a slow deep breath as the medication canister is pressed and holding the breath for 5 to 10 seconds and then exhaling. Cleaning the inhaler regularly is recommended to prevent a buildup of medications. Spacers or chambers can help patients inhale the aerosol and help decrease the deposition of the medication in the mouth or throat.

Complications

The medical personnel should recognize the potential complications of each route of medication administration. The parenteral route can cause pain or discomfort in the area of application, bleeding, bruising, infection, or inflammation. Infiltration is a common complication of the intravenous route whereby the intravenous fluid or medication enters the surrounding tissue and not the vein. It is not deemed severe unless the infiltrated medication is a compound that may damage the surrounding tissue, such as a chemotherapeutic agent or a vesicant, in which case the complication is termed extravasation, and this may lead to tissue necrosis. Although the intravenous route has the benefit of rapidly delivering drugs to patients, this may cause nonspecific severe cardiopulmonary effects, and healthcare personnel should closely monitor the patients.

For intramuscular injections, there are site-specific complications to be aware of. In deltoid muscle injection, an unintentional injury to radial and axillary nerves with resultant paralysis or neuropathy may not always resolve. Complications associated with the subcutaneous route are more medication-specific. For instance, in subcutaneous insulin, lipohypertrophy or lipoatrophy can develop, leading to slower or incomplete insulin absorption at the injection site. Therefore, using different injection sites is recommended for patients.

In the intranasal route, interseptal nasal perforation had been reported in some patients, particularly those using intranasal steroids for a prolonged period. Rebound congestion in patients on chronic nasal decongestants is seen as the sinusoid vasculatures do not respond as well to the adrenergic drug with prolonged use and result in a hyperemic, congested mucosa. Complications associated with inhaled medications are also often medication-specific. For instance, inhaled corticosteroids can cause local deposition that leads to thrush or dysphonia, and sometimes cough, throat irritation, and contact hypersensitivity also have been reported.