Routes of Drug Administration | Academically Australia

Routes of Drug Administration

May 11, 2024 3 min read
Routes of Drug Administration

Routes of drug administration are diverse and can be classified into local and systemic methods. Local routes target specific areas of the body to achieve localised effects, while systemic routes deliver medications into the bloodstream for distribution throughout the body. 

Understanding the different routes of drug administration is essential for healthcare professionals to optimise treatment outcomes and patient care.

Local Route

Local routes of drug administration involve delivering medications directly to a specific site in the body, often to achieve a localised effect. Common methods include:

Topical: Applied to the skin, medications can treat surface conditions like rashes, infections, or pain. Examples include creams, ointments, and patches.

Example:

  • Hydrocortisone cream for skin inflammation
  • Bacitracin ointment for minor cuts and wounds
  • Clotrimazole cream for fungal infections like athlete's foot
  • Lidocaine patch for localised pain relief

Ophthalmic: Administered to the eyes, these medications treat eye infections, glaucoma, or inflammation. They come in the form of drops, ointments, or gels.

Example:

  • Tobramycin eye drops for bacterial eye infections
  • Artificial tears for dry eyes
  • Cyclopentolate eye drops for dilating the pupils during eye exams
  • Fluorometholone ointment for inflammation of the eye

Otic: Delivered into the ear canal, these medications treat ear infections or inflammation. They can be in the form of drops or sprays.

Example:

  • Acetic acid ear drops for treating swimmer's ear (otitis externa)
  • Hydrocortisone-benzalkonium ear drops for ear inflammation and itching
  • Antibiotic ear drops like ofloxacin for treating ear infections

Nasal: Administered into the nasal cavity, medications can treat allergies, sinus infections, or nasal congestion. They are typically in the form of sprays or drops.

Example:

  • Fluticasone nasal spray for allergic rhinitis
  • Oxymetazoline nasal spray for nasal congestion
  • Ipratropium nasal spray for runny nose associated with allergies or colds

Inhalation: Inhaled medications are delivered directly to the respiratory system to treat conditions like asthma, COPD, or respiratory infections. They can be inhaled through inhalers or nebulizers.

Example:

  • Albuterol inhaler for relieving asthma symptoms
  • Corticosteroid inhalers like fluticasone for long-term asthma control
  • Ipratropium bromide inhaler for chronic obstructive pulmonary disease (COPD)

Rectal: Administered into the rectum, medications can treat conditions like haemorrhoids, constipation, or inflammatory bowel disease. Examples include suppositories or enemas.

Example:

  • Hydrocortisone suppositories for treating hemorrhoids
  • Mesalamine enemas for treating inflammatory bowel disease (ulcerative colitis)
  • Glycerin suppositories for relieving constipation

Systemic Route

Systemic routes of drug administration involve delivering medications into the bloodstream, allowing them to distribute throughout the body to exert their effects. Common systemic routes include:

Oral: Administered via the mouth, oral medications are swallowed and absorbed through the gastrointestinal tract. They include tablets, capsules, liquids, and suspensions. Oral administration is convenient and suitable for many medications, but absorption can be affected by factors like food and stomach acidity. 

Example

  • Acetaminophen
  • Aspirin 
  • Ibuprofen 
  • Omeprazole 
  • Metformin

Intravenous (IV): Medications are injected directly into a vein, providing rapid and complete absorption. This route is used for critical conditions requiring immediate effects, precise dosing, or drugs that are poorly absorbed orally. 

Example

  • Antibiotics like vancomycin or ceftriaxone
  • Chemotherapy drugs like cisplatin 
  • Emergency medications like epinephrine 
  • Fluids and electrolytes for hydration

Intramuscular (IM): Medications are injected into a muscle, where they are absorbed gradually into the bloodstream. IM injections are commonly used for vaccines, antibiotics, and certain medications that require sustained release. 

Example

  • Vaccines like the influenza vaccine 
  • Antibiotics like penicillin G
  • Analgesics like morphine 
  • Contraceptive injections

Subcutaneous (SC): Medications are injected into the tissue layer just beneath the skin, allowing for slow and steady absorption. This route is used for medications requiring sustained release, such as insulin or some hormones. 

Example

  • Insulin
  • Enoxaparin an anticoagulant
  • Growth hormone therapy like somatropin (Genotropin)
  • Epinephrine auto-injectors for severe allergic reactions (EpiPen)

Transdermal: Medications are applied to the skin and absorbed into the bloodstream over time. Transdermal patches deliver drugs continuously, providing a steady release over hours or days. This route is often used for medications like nicotine patches, hormone therapy, or pain management. 

Example

  • Nicotine patches
  • Hormone replacement therapy patches like estradiol
  • Fentanyl patches for pain management
  • Scopolamine patches for motion sickness

Rectal: Medications are administered into the rectum, where they are absorbed into the bloodstream through the rectal mucosa. This route can be used when oral administration is not feasible, such as for patients who are vomiting or unable to swallow. 

Example

  • Acetaminophen suppositories
  • Bisacodyl suppositories for constipation relief
  • Mesalamine for inflammatory bowel disease
  • Antiemetics like promethazine for nausea and vomiting

Conclusion

Routes of drug administration allows healthcare professionals in deciding treatment approaches to individual patient needs and medical conditions. 

By understanding the characteristics and applications of each route, healthcare providers can optimise the efficacy, safety, and convenience of drug therapy, ultimately improving patient outcomes and quality of care.

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Dr. Indu K
Dr. Indu K
about the author

Dr. Indu K is a dentist with one year of clinical experience. She seamlessly transitioned into content writing three years ago. Her passion lies in making complex medical information accessible to everyone. She uses her unique blend of medical knowledge and exceptional writing skills to bridge the gap between healthcare and the general audience.