Paraffin
Paraffin (also known as liquid paraffin or mineral oil) is a widely used **lubricant laxative** and **ophthalmic tear substitute** in veterinary medicine. Orally, it is used to manage constipation and hairballs (especially in cats). Topically, it is used to lubricate the eyes and prevent tear evaporation. > **Clinical Pearl:** Extreme caution must be used when administering liquid paraffin orally due to the severe risk of **aspiration pneumonia**. It is tasteless and does not elicit a normal gag reflex, making aspiration highly likely if force-fed.
Mechanism: Paraffin has two distinct mechanisms depending on the route of administration: * **Gastrointestinal (Laxative):** Acts as an emollient laxative. It coats the feces and intestinal mucosa → interferes with intestinal water resorption → softens stools and facilitates passage. * **Ophthalmic (Lubricant):** Acts as a lipid-based tear substitute. It mimics the **lipid layer** of the tear film → prevents aqueous tear evaporation and protects the corneal surface.
Routes of administration
Contraindications
- Dysphagia or impaired gag reflex
- Vomiting patients
- Concurrent use with docusate sodium
- Prolonged daily use (due to vitamin malabsorption)
Adverse effects
- Aspiration pneumonia (if inhaled during oral administration)
- Anal seepage / oily perianal soiling
- Decreased absorption of fat-soluble vitamins (with chronic oral use)
- Granulomatous reactions (if absorbed into intestinal mucosa)
Drug interactions
- Fat-soluble vitamins (A, D, E, K) · Decreased intestinal absorption of vitamins with chronic paraffin use · moderate
- Docusate sodium · May increase the systemic absorption of mineral oil, leading to granuloma formation · major
Monitoring
- Resolution of constipation
- Signs of respiratory distress or coughing (indicating possible aspiration)
- Fecal consistency
Overdose
Overdosage via the oral route primarily results in **diarrhea**, **anal seepage**, and profound **perianal soiling**. Chronic overdosage may lead to deficiencies in fat-soluble vitamins.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.