Intramuscular injection skin irritation

Localized tissue irritation can be seen from the intramuscular (IM) route. This is especially an issue when the formulation pH differs from the pH of the surrounding tissue or when precipitation of poorly soluble drugs occurs. Incorrect administration of IM injections is probably the most important factor that causes local adverse effects. Local skin irritation can also be seen with transdermal delivery systems due to the alcohols, nonionic surfactants, and adhesives. 

Benzyl benzoate is widely used as a 25% v/v topical application in the treatment of scabies and as an excipient in intramuscular injections and oral products. Adverse reactions to benzyl benzoate include skin irritation and hypersensitivity reactions. Oral ingestion may cause harmful stimulation of the CNS and convulsions. 

Lewisite (15-chlorovinyldichloroarsine) was synthesized in 1918 for use as a weapon, and its clinical effects are similar to those of mustard in many respects, although the cellular mechanisms are believed to differ. However, unlike mustard. Lewisite liquid or vapor produces irritation and pain seconds to minutes after contact. Immediate decontamination may limit damage to skin or eyes, and intramuscular injections of a specific antidote, dimercaprol, or British antiLewisite (BAL) will reduce the severity of systemic effects. BAL has toxic effects of its own, however, and must be used with care. 

Iron salts occasionally cause gastrointestinal irritation, nausea, vomiting, constipation, diarrhea, headache, backache, and allergic reactions. The stools usually appear darker (black). Iron dextran is given by the parenteral route Hypersensitivity reactions, including fatal anaphylactic reactions, have been reported with the use of this form of iron. Additional adverse reactions include soreness, inflammation, and sterile abscesses at the intramuscular (IM) injection site Intravenous (IV) administration may result in phlebitis at the injection site When iron is administered via the IM route, a brownish discoloration of tlie skin may occur. Fhtients with rheumatoid arthritis may experience an acute exacerbation of joint pain, and swelling may occur when iron dextran is administered. 

As indicated in Table 2.1, drugs may be injected into veins, muscles, subcutaneous tissue, arteries, or into the subarachnoid space of the spinal canal (intrathecal). For obvious reasons, intraarterial and intrathecal injections are reserved for specialized drug administration requirements, such as regional perfusion of a tumor with a toxic drug or induction of spinal anesthesia, respectively. Therefore, the more routine injection routes are intravenous (IV), intramuscular (IM), and subcutaneous (SC). Because these three modalities involve skin puncture, they carry the risks of infection, pain, and local irritation. 

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