Table 1 Characteristics of the included studies

Gates 1972 [13]

2000 adults undergoing IVP

History of allergic reactions taken, patients with positive history included

Diphenhydramine 10 mg ivi 1 minute prior to contrast

30–60 ml Renograffin 60 (Ionic)

Not defined

Small 1982 [14]

220 adults undergoing IVP

Patients taking anti-histamines excluded

Chlorpheniramine 10 mg sci 15 minutes prior to contrast

Not recorded

Hives, generalised pruritis

Bertrand 1992 [16]

400 adults undergoing IVP, CT or lower limb venography

Patients with history of allergy, atopy, drug sensitivity or previous reactions to contrast excluded

Hydroxyzine 100 mg po 12 hours prior to contrast

Meglumine ioxaglate (Ionic)

Nausea, vomiting, hives, urticaria, flushing, facial oedema, wheezing, dyspnoea, laryngeal oedema, hypotension, death

Ring 1985 [15]

800 adults undergoing IVP

Patients with previous life-threatening contrast reaction excluded

1. Prednisolone 250 mg ivi, 5 minutes prior to contrast

2. Clemastin 0.03 mg/kg ivi, 5 minutes prior to contrast

3. Clemastin 0.03 mg/kg ivi + cimetidine 5 mg/kg vi, 5 minutes prior to contrast

100 ml meglumine amidotrizoate (ionic)

Flush, urticaria, angioedema, respiratory symptoms, vomiting, tachycardia, hypotension

Lasser 1987 [17]

6763 adults

undergoing IVP or contrast enhanced CT

Patients with previous severe reaction excluded. Patients with general allergies, drug allergies and previous non life threatening reactions were included

1. Methylprednisolone 32 mg po two hours prior to contrast

2. Methylprednisolone 32 mg o the night before + two hours prior to contrast

Various ionic contrast agents

Grade 1: emesis, nausea, sneezing, vertigo Grade II: Hives, fever, hills, Grade III: Shock, bronchospasm, laryngospasm, laryngeal oedema, loss of consciousness, angioedema

Lasser 1994 [18]

1155 adults undergoing IVP or contrast enhanced CT

Patients with allergies including previous reactions to contrast were included

Methylprednisolone 32 mg po the night before and two hours prior to the contrast

Iohexol, Ioversol (non-ionic)

As per Lasser 1987