Meptid versus Pethidine

UK Midwifery Archives

These archives contain extracts from discussions held on the UK Midwives and Consumers email list, a discussion group for people interested in midwifery in the UK. Open to midwives, students, mothers, and anyone interested in improving maternity services in UK. Posts in these archives express the views of the individual authors, and not those of the Association of Radical Midwives.

Analgesia: Meptid versus Pethidine

Several women have asked me about Meptid. We don’t offer this analgesia in our Unit, and there seems to be very little info around. Does anybody have experience of using this drug in labour? Is it true that it has less of a depressive effect on the baby than Pethidine? If its so good, why isn’t it more widely used? Cost, tradition – or other factors?

Hannah, midwife, UK

I used to use it quite a bit as I hate Pethidine.

Is it true that it has less of a depressive effect on the baby than Pethidine?


If its so good, why isn’t it more widely used? Cost, tradition – or other factors?

If I remember correctly it’s about 3-4 times more expensive as Pethidine and this governs its use where I work at present. Certainly less sedating on the woman and provides as much pain relief (if you can call it that) as Pethidine.


Hinchingbrooke Hospital, Huntingdon, Cambs, has used Meptid since the unit opened in 1983 and yes, it’s very likely that it’s not more widely used due to the cost – if I remember correctly about 7 pounds per ampoule. In my experience, its definitely preferable to Pethidine in terms of not sedating babies or women. It was given in a 100mg dose and only two doses maximum.


The studies I found relating to the issue said that, in terms of pain relief, Meptid fared better than pethidine.

At my local unit the midwives are very reluctant to offer it as an alternative, particularly for primips. Their rationale seems to be that it is less effective in relieving pain than pethidine. They also claim that anecdotally it does have a depressive effect on the respiratory function of the baby, and there is no antidote. In fact, according to the manufacturers of meptid, Narcan can be used in exactly the same way if there appears to be a problem with the baby breathing at birth.

My reasoning when discussing meptid and pethidine is that when women start to believe that they need an injection to enable them to cope with labour, they are frequently in advanced labour, often in transition, and the effect of giving anything will make them feel that they are able to cope better. As we all know, the love and support of a constant presence during labour is far more effective than any drugs controlled or otherwise.


March 1999 British National Formulary

Meptid 1ml ampule – 100mg = £1.92

Pethidine 2ml ampule – 100mg = 42p

Pethidine 1ml ampule – 50mg = 40p

I had meptid towards the end of my first labour. I found it dulled the pain of the start of a contraction, but I felt the second half of each contraction at full fury.

Of course, they didn’t tell me til after the injection that I’d have to stay on the bed once I had it. I know it’s supposed to be a weaker form of pethidine, and I would say the emphasis is on ‘weak’.

Lesley M

If I remember correctly, about a year ago we had a woman who obtained meptid from her GP for pain relief at a home birth because of the above reasons. However her baby was born shortly after its administration and the baby was severely respiratorily depressesd, unlike pethidine there was no equivalent reversing agent (ie neonatal narcan). Nightmare resucitation and transfer to hospital followed, although all was eventually OK, apart from the obvious trauma.

I know the midwives at the time felt unable to use Narcan in this situation. Does anyone know if this would have been an appropriate action or whether there is another drug specifically for use in this situation?

Some pharmacy references on Meptid:

Pronunciation (mep TAZE i nol)
Brand Names Meptid®; Nestan®
Synonyms Meptazinol Hydrochloride

Use Investigational in U.S.: Acute analgesic agent; also used to diminish Jarisch-Herxheimer reaction

Mechanism of Toxic Action: A centrally acting opioid agonist-antagonist agent with cholinergic activity

Adverse Reactions: All adverse effects are seen frequently with parenteral administration as compared to oral administration.

Central nervous system: Drowsiness, dizziness, euphoria, headache, amnesia, hallucinations, dysphoria

Gastrointestinal: Nausea, vomiting, xerostomia, dyspepsia

Ocular: Slight miosis, blurred vision

Miscellaneous: Diaphoresis

Signs & Symptoms of Acute Overdose: Respiratory depression


Peak effect: Oral: 1-2 hours Parenteral: 0.5-1 hour

Distribution: Vd: 2-3 L/kg

Protein binding: 23% to 27%

Metabolism: Hepatic

Bioavailability: Oral: 4% to 10%

Half-life: Neonates: 3.4 hours Adults: 2 hours (adult men); 1.4-1.7 hours (adult women)

Elimination: Primarily renal (plasma clearance ~100 L/hour)

Effective analgesia: Oral: 4 hours

Usual Dosage

Children: I.M. (in lateral thigh): 1 mg/kg

Analgesia: Oral: 200 mg every 3-6 hours Epidural: 30-90 mg (in 10 mL of normal saline) I.M.: 75-100 mg every 2-4 hours I.V.: 50-100 mg slowly every 2-4 hours; continuous I.V.: Loading dose of 50 mg I.V. followed by 0.5 mg/kg/hour for up to 1 day

Herxheimer reaction: I.V.: 300-500 mg

Contraindications: Hypersensitivity to meptazinol, respiratory depression, acute alcoholism, head trauma

Warnings: Use with caution in patients who are hypothyroid, adrenal insufficiency, renal or liver disease, prostate hypertrophy, shock, obstructive bowel, myasthenia gravis, elderly, bronchospastic disease, hypersensitive to other opioids; dependent on opioids; history of drug abuse

Dosage Forms

Injection, as hydrochloride: 100 mg/mL

Tablet, as hydrochloride: 200 mg

Reference Range: Peak serum level after a 200 mg oral dose: 10-110 ng/mL; peak plasma level after a 50 mg I.V. dose: ~270 ng/mL

Overdosage Treatment: Supportive therapy: Naloxone hydrochloride (0.4-2 mg I.V., S.C., or through an endotracheal tube); a continuous infusion (at 2/3 the response dose/hour) may be required; opioid-induced myoclonus may respond to dantrolene (50-150 mg/day); higher than usual doses of naloxone may be necessary to treat respiratory depression

Antidote(s): Naloxone

Pregnancy Implications: No teratogenic effects known; can cross the placenta

Additional Information ~1/10 as potent as morphine with miosis and constipation occurring less frequently structurally similar to pentazocine

Specific References: Davison AG, Collinson PO, Assefi AR, et al, “Meptazinol Overdose Producing Near Fatal Respiratory Depression,”Hum Toxicol, 1987, 6(4):331.

Medline Abstracts on Meptid

TITLE: Types of intra-muscular opioids for maternal pain relief in labour. AUTHORS: Elbourne D; Wiseman RA AUTHOR AFFILIATION: Medical Statistics Unit, London School of Hygiene and Tropical Medicine, Room 121, Keppel Street, London, UK, WC1E 7HT. SOURCE: Cochrane Database Syst Rev 2000;(2):CD001237 CITATION IDS: PMID: 10796255 UI: 20257345 ABSTRACT: BACKGROUND: Pethidine is the most widely used intra-muscular opioid for the relief of labour pain. However concerns have been raised about its effectiveness and the possibility of depressing respiration in newborns. OBJECTIVES: The objective of this review was to assess the effects of different opioids (and different doses of the same opioid) administered intra-muscularly in labour. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group trials register, the Cochrane Controlled Trials Register (Cochrane Library, issue 4, 1997) and reference lists of articles. SELECTION CRITERIA: Randomised trials comparing the effects of different currently used opioids (and different doses of the same opioid) administered intramuscularly in labour for women who request systemic analgesia. DATA COLLECTION AND ANALYSIS: Two reviewers assessed trial quality and extracted data. Analysis was based on the groups as randomly allocated.
MAIN RESULTS: Sixteen trials were included. There were problems with methodological quality of some of the trials, and lack of consistency in the way various outcomes were reported. There was no evidence of a difference between pethidine and tramadol in terms of pain relief, interval to delivery, or instrumental or operative delivery. There appeared to be more adverse effects such as nausea and vomiting and drowsiness with pethidine. Maternal pain relief seemed almost identical between the meptazinol and pethidine groups, whether assessed as maternal satisfaction with pain relief, visual analogue scales, or use of other pain relief, but meptazinol gave rise to slightly more side effects. Maternal satisfaction with pain relief appeared similar for pentazocine and pethidine, with more frequent nausea and vomiting with pethidine.
REVIEWER’S CONCLUSIONS: There is not enough evidence to evaluate the comparative efficacy and safety of the various opioids used for analgesia in labour.

TITLE: A double-blind study comparing meptazinol and pethidine for pain relief in labour.
AUTHOR AFFILIATION: Department of Obstetrics and Gynecology Y, University Hospital of Copenhagen, Denmark.
SOURCE: Eur J Obstet Gynecol Reprod Biol 1987 Sep;26(1):15-8
CITATION IDS: PMID: 3666261 UI: 88030321
ABSTRACT: A double-blind comparison of meptazinol 100 mg and pethidine 75 mg as analgesics during the first stage of labour was undertaken in 199 patients. Injections were allowed to be repeated at intervals of 2 h to a maximum of three doses. There were only minor differences between the two drugs with regard to pain relief and no differences in the need for supplementary epidural and pudendal blocks and neonatal status and behaviour. It is concluded that meptazinol and pethidine are of equal clinical value as analgesic injections during the first stage of labour.
TITLE: A comparison of the effects of maternally administered meptazinol and pethidine on neonatal acid-base status.
AUTHORS: de Boer FC; Shortland D; Simpson RL; Clifford WA; Catley DM
SOURCE: Br J Obstet Gynaecol 1987 Mar;94(3):256-61
CITATION IDS: PMID: 3567124 UI: 87185321
ABSTRACT: A randomized double-blind study compared the effects of equi-analgesic doses of maternally administered meptazinol (1.5 mg/kg) and pethidine (1.5 mg/kg) on neonatal acid-base status. Heel-prick samples were taken for assessment of acid-base status at 10 and 60 min after delivery. Maternal antenatal history, details of labour and neonatal status at delivery were also recorded. Meptazinol produced less neonatal respiratory depression than pethidine: the mean 10 min acid-base data from 16 infants whose mothers received pethidine were indicative of a respiratory acidosis (pH 7.13, SD 0.08, PCO2, 9.11, SD 2.2 kPa; standard bicarbonate 22.3, SD 3.1 mmol/l). This was not evident in the mean acid-base data from 16 infants whose mothers received meptazinol (pH 7.23, SD 0.07; PCO2 6.83, SD 1.6 kPa; standard bicarbonate 20.9, SD 4.2 mmol/l). The mean pH and PCO2 in the two treatment groups were significantly different (P less than 0.002) at 10 min but not at 60 min after delivery.
TITLE: Pethidine compared with meptazinol during labour. A prospective randomised double-blind study in 1100 patients.
AUTHORS: Morrison CE; Dutton D; Howie H; Gilmour H
SOURCE: Anaesthesia 1987 Jan;42(1):7-14
CITATION IDS: PMID: 3826577 UI: 87154266
ABSTRACT: A randomised double-blind comparison of pethidine and meptazinol used as analgesics in labour was carried out in 1,100 consecutive women who would normally have received intramuscular pethidine. Pain assessments at 30-minute intervals were made independently by patients and midwives. Maternal and neonatal side effects were noted. The babies’ requirements for resuscitation and weight changes in the first 5 days were studied. There was no difference in the analgesia provided by the two drugs; the pattern of side effects was similar, but the incidence of vomiting was greater following meptazinol administration. The babies in the two groups were similar with respect to resuscitation received, weight gains or losses and the incidence of clinical neonatal jaundice. The most striking findings were the poor quality of pain relief experienced by both groups following parenteral analgesics and the high incidence of side effects.

TITLE: Comparative study of meptazinol and pethidine for the relief of pain in labour.
AUTHORS: Sheikh A; Tunstall ME
SOURCE: Br J Obstet Gynaecol 1986 Mar;93(3):264-9
CITATION IDS: PMID: 3516202 UI: 86187641
ABSTRACT: A double-blind comparison of pethidine and meptazinol in the relief of pain during labour was undertaken in 205 healthy women. The protocol allowed 100 mg of the test drug to be repeated at intervals of 2 h to a maximum of three doses. It was noteworthy that only 29 mothers were given a second dose of narcotic. Every woman receiving one injection of meptazinol complained of moderate to severe pain after 2 h; 97% of those receiving one injection of pethidine were complaining of moderate to severe pain after 2 h. There was no difference between the two drugs with regard to pain relief or in side-effects both in mother and baby.

TITLE: A study of the effect of meptazinol on fetal heart rate patterns.
AUTHORS: Hanretty K; Whittle M; McGowan L
SOURCE: Pharmatherapeutica 1985;4(5):319-21
CITATION IDS: PMID: 4070324 UI: 86068295
ABSTRACT: A study was carried out in 40 women undergoing labour to investigate the effect of 100 to 150 mg meptazinol intramuscularly, given alone for the relief of labour pain, on fetal heart rate patterns. Patients were monitored continuously using a fetal scalp electrode attached to a fetal monitor, and fetal heart rate patterns recorded on the cardiotocograph. Traces were interpreted for 2 hours preceding and 2 hours after administration of meptazinol using a 12-point scoring system to quantify the variables of baseline rate and variability and the presence or absence of variable or late decelerations. All babies were born live and, except for 1 delivered by emergency caesarean section under general anaesthesia, none had an Apgar score less than 8 at 1 minute. Analysis of the cardiotocograph traces showed that adverse changes, such as loss of variability, were not significantly associated with the use of meptazinol.

TITLE: Double-blind comparison of meptazinol and pethidine in labour.
AUTHORS: Nicholas AD; Robson PJ
SOURCE: Br J Obstet Gynaecol 1982 Apr;89(4):318-22
CITATION IDS: PMID: 7041955 UI: 82182775
ABSTRACT: The analgesic efficacy and safety of intramuscular meptazinol and pethidine in the first stage of labour were compared in a randomized double-blind trial in 358 patients. Pain relief was measured on a verbal rating scale, maternal side effects were recorded and neonatal outcome assessed in the first 24 h. Pain relief during the first hour after injection was significantly greater in the meptazinol than in the pethidine group at 45 and 60 min. Thereafter, there was no difference between the treatments, and the duration of action was approximately the same. Twenty-eight per cent of patients experienced side effects after meptazinol compared with 35% after pethidine. The commonest were nausea and vomiting with a similar incidence in both groups. Most of the neonatal observations revealed no difference between the two drugs, but significantly more babies whose mothers had received meptazinol had an Apgar score of greater than or equal to 8 at 1 min after birth.

TITLE: A comparison of meptazinol and pethidine for pain relief during the first stage of labour.
AUTHORS: Nel CP; Bloch B; Rush JM
SOURCE: S Afr Med J 1981 Jun 13;59(25):908-10
CITATION IDS: PMID: 7015539 UI: 81201335
ABSTRACT: Meptazinol and pethidine were compared in a double-blind randomized trial with regard to analgesia during the first stage of labour. It was concluded that neither drug is effective for sustained pain relief, and that there is no advantage of one over the other. However, neither drug affected maternal condition as reflected by respiratory rate, pulse rate and blood pressure, nor was any detrimental effect noted on the condition of the newborn infant. The critical reassessment of traditional drugs for analgesia in labour is suggested.

TITLE: Preliminary experience of the use of meptazinol as an obstetric analgesic.
AUTHORS: Jackson MB; Robson PJ
SOURCE: Br J Obstet Gynaecol 1980 Apr;87(4):296-301
CITATION IDS: PMID: 7000166 UI: 81039811
ABSTRACT: Following an open pilot trial, meptazinol [m(3-ethyl-1-methyl-hexahydro-1-H-azepin-3-yl) phenol hydrochloride] was compared to pethidine in a single-blind study in women requiring analgesia during labour. Meptazinol provided significantly better analgesia than pethidine with similar but possibly less distressing maternal side effects. There were no obvious adverse effects in the newborn.

Links to other sources of information:

See also page on Pethidine – midwives’ and women’s views, and safety issues.

Some pharmacy references on Meptid:

AH updated 4 April 2001

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Posted on

April 12, 2013

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