Annual Scientific Meeting - 2001

Life after Droperidol

Dr JK Orton, Consultant Anaesthetist, Royal Oldham Hospital

For those acute pain units that used a combination of antiemetic and opioid for their PCA regime, Janssen’s decision to cease production of parenteral droperidol was vexatious to say the least; droperidol, as reflected by the literature, was the gold standard anti-emetic for this purpose. This decision followed alerts of prolonged QT interval in chronic oral administration. Withdrawal of the oral product meant the parenteral product was no longer viable and all production of droperidol has ceased.

The current situation is that most units have a few weeks supply, being eked out by various strategies.

The strategies available are:

1.      Reduce wastage by smaller quantities in prefilled syringes

2.      Resourcing

3.      Abandoning in-syringe antemetic

4.      Alternative anti-emetics

1.      Reduce wastage
This is only of temporary value and many units’ supply is down to a few weeks.

2.      Resourcing
This may be possible if generic production has continued elsewhere in the world where oral droperidol continues to be licenced.

3.      Abandoning in-syringe anti-emetic
This is current practice in many units; for them the topic of this talk is not an issue. Emetic events under PCA therapy without routine anti-emesis run at 50 to 70%. The ‘pure opioid’ units depend on reliable ward administration of anti-emetics.

4.      Alternative drugs
Tramèr and Walder (1999) systematically reviewed 14 studies on prophylactic anti-emetics during PCA use. Their search extened up to May 1998. Essentially they established that droperidol the best documented drug and at concentrations studied was effective. They concluded regimes at lower concentrations needed to be explored.
The main alternative was ondansetron. Interestingly in the few studies quoted, while the incidence of vomiting was reduced, that of nausea was not. This was supported by a recent study by Millo et al, (2001) that compared droperidol with ondansetron. The nausea rate for ondansetron was 47% similar to that found in Tramèr’s meta analysis. (Although the rate for droperidol in Millo’s study was not significantly different).
Other drugs that have been studied are hyoscine (as a patch), promazine, cyclizine, low dose propofol, tropisetron. Acupuncture has also been studied. Cyclizine as an in-syringe antiemetic has only one study to its name, Walder and Aitkenhead (1995) but in view of its established role in intervention therapy a number of units are have either begun its use or are considering it. It has also been the subject of increased commercial promotion. Buccal prochlorperazine as a form of intervention therapy has been suggested (Williams and Smith, 1999) and advertised!

 The remainder of the lecture will make reference to some of the issues (pharmaceutical and organisational) in adopting alternatives to droperidol and a brief nod to the politics of emesis will be made (Pollard 2001).

References

Tramèr MR, Walder B. Efficacy and adverse events of prophylactic antiemetics during patient controlled analgesia therapy: a quantitative systematic review. Anesthesia and Analgesia 1999; 88: 1354-61

Millo J, Siddons M, Innes RJ, Laurie PS. Randomised double-blind comparison of ondansetron and droperidol to prevent postoperative nausea and vomiting associated with patient-controlled analgesia. Anaesthesia 2001; 56: 60-65

Walder AD, Aitkenhead AR. A comparison of droperidol and cyclizine in the prevention of postoperative nausea and vomiting associated with patient controlled analgesia. Anaesthesia 1995; 50: 654-656

Williams PI, Smith M. An assessment of prochlorperazine buccal for the prevention of nausea and vomiting during intravenous patient-controlled analgesia with morphine following abdominal hysterectomy. European Journal of Anaesthesiology 1999; 16: 638-645

Pollard BJ. Guest editorial: Now you see it, now you don’t! Bulletin of the Royal College of Anaesthetists May 2001: 298-299

Grassby PF, Hutchings L. Drug combinations in syringe drivers: the compatibility and stability of diamorphine with cyclizine and haloperidol. Palliative Medicine 1997; 11: 217-224