Pain on injection

The effect of isotonicity on reducing pain on injection is somewhat uncertain, although it may at least reduce tissue irritation. Pain on injection may occur... 

Pain on injection To minimize the likelihood of pain or inflammation at the injection site, administer flumazenil through a freely flowing IV infusion into a large vein. Local irritation may occur following extravasation into perivascular tissues. 

Etomidate may cause pain on injection and may produce myoclonic muscle movements in approximately 40% of patients during its use as an induction anesthetic. In addition, etomidate can suppress the adrenocortical response to stress, an effect that may last up to 10 hours. 

Water-soluble avoids the use of solubilising agents No pain on injection, no venous or tissue damage following extravasation Pharmacokinetics High lipid solubility, a high proportion of unbound, unionised drug to facilitate... 

Injections of thiopentone rarely cause pain on injection or evidence of venous irritation and the incidence of venous thrombosis is very low at 3-4%. 

Pain on injection is more common (8-20%) than with thiopentone, especially if a small vein is used for administration but can be reduced by flushing the vein with lidocaine (lignocaine) prior to methohexitone administration. 

Pain on injection. The 35% propylene glycol solvent is a significant contributor to the high incidence of pain on injection (80% with small veins, 10% with large veins) that can be further reduced by the prior administration of 1% lidocaine (lignocaine). 

Venous thrombosis is more common than with other agents. As with pain on injection, the incidence is iess when iipofundin is used as the soivent. 

Etomidate causes a high incidence of pain on injection, myoclonic activity, and postoperative nausea and vomiting. The involuntary muscle movements are not associated with electroencephalographic epileptiform activity. Etomidate may also cause adrenocortical suppression via inhibitory effects on steroidogenesis, with decreased plasma levels of cortisol after a single dose. Prolonged infusion of etomidate in critically ill patients may result in hypotension, electrolyte imbalance, and oliguria because of its adrenal suppressive effects. 

The most commonly used salts in vaccine formulations are sodium chloride, sodium phosphate, succinic acid, and sodium borate. The concentrations of the salts used in any given formulation are based on isotonicity, pH, and other stabilizers being used in the formulations. A typical range is from 5 to 20 mM salt concentration. These concentrations are also selected to reduce pain on injection and to accord rapid normalization with physiological fluid. Surfactants used in MF59 emulsion include Tween 80 and sorbitan trioleate. 

One must also remember that precipitation can occur on dilution with other intraverarixili Investigation of dilution in common parenteral vehicles, for example, normal saline, 5% dextrose solution, or likely coadminstered drug products should be conducted for solubility and stability purposes before recommending such procedures. Phlebitis, hemolysis, and pain on injection are also issues for parenteral formulations containing cosolvents. 

Clarithromycin Lovell etal. (1994) Emulsion formulation decreased pain on injection... 

Decrease pain on injection Clindamycin Clindamycin phosphate30... 

Models that do assess pain on injection are the rat paw lick and mouse scratch models. In the paw lick model, the drug formulation is injected into the pad of the hindfoot, and the number of times the rat licks the paw is counted. The mouse scratch test is similar except that the formulation is injected subcutaneously on the back, and the number of times the mouse scratches the injection site is counted. 

Protection of drugs against the environment (moisture, light, heat, and/or oxidation) and vice versa (prevention of pain on injection) ... 

Etomidate, a non-barbiturate anesthetic, is considered to be safe, especially in patients with hemodynamic instability. The most common complications of using etomidate are venous sequelae, pain on injection (1), and involuntary muscle movements (SED-11, 211) (2). 

In 104 patients, the freqnency of pain on injection of etomidate was 32-53% and was severe in 5-20% of patients (5). The freqnency of involnntary movements was 15-35%. The freqnency of both pain and involuntary muscle movements was least when fentanyl 2.5 pg/kg was given before etomidate. There was no significant relation between pain and muscle movement. A medium-chain triglyceride and soya bean emulsion formulation has been used for anesthetic induction, in an attempt to reduce the unwanted adverse effects of pain on injection and thrombophlebitis (6). 

Kawar P, Dundee JW. Frequency of pain on injection and venous sequelae foUowing the I.V. administration of certain anaesthetics and sedatives. Br J Anaesth 1982 54(9) 935-9. 

Intradermal local anesthetic solutions can cause considerable pain on injection. Additives, such as hyaluronidase, which are used to enhance the analgesic effect of local anesthetics, can often exacerbate this (165). Infiltration from the inside of a wound can be less painful than through intact skin (166). 

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