Treatment

• NSAID's:
  • for example, mefenamic acid, naproxen, and ibuprofen
  • these inhibit the synthesis of prostaglandins and are effective in 80-90% of cases due to their effect in reducing uterine contraction
  • if periods are regular, treatment will be more effective if initiated one day before menstruation begins - check the BNF for contraindication and interactions
    
    
• combined oral contraceptives:
  • reduce menstrual flow and inhibit ovulation - primary dysmenorrhoea is generally associated with ovulation, thus the oral contraceptive pill will often relieve primary dysmenorrhoea
  • they are particularly useful in situations where contraception also, is required
  • they may be combined with NSAID's
  • long-term continuous oral contraceptives can be used in women with symptomatic endometriosis and menstrual-related pain - some have suggested taking the oral contraceptive for longer periods with shorter intervals to avoid heavy periods, which could be a distressing side-effect in some women (1)
  • a systematic review concluded that there is limited evidence for pain improvement with the use of the OCP (both low and medium dose oestrogen) in women with dysmenorrhoea. There is no evidence of a difference between different OCP preparations (2)
    
    
• other analgesia such as paracetamol has a more variable efficacy - considered if NSAIDs are contraindicated
  
  
• alverine citrate (Spasmonal) is licensed for the treatment of dysmenorrhoea - this drug has an anticholinergic antispasmodic that relaxes the uterine smooth muscle by acting on intramural parasympathetic ganglia. Note though that there is a lack of published evidence regarding its efficacy

If the above measures are ineffective then advice re: further management should be sought - other treatments that may then be used include the levonorgestrel-releasing intrauterine system, tocolytic agents such as salbutamol, calcium channel blocking agents such as nifedipine, progestogens, glyceryl trinitrate patches, nondrug treatments such as transcutaneous electrical nerve stimulation (TENS) or behavioural therapy.

If there is doubt concerning the diagnosis then pelvic pathology may be investigated by laparoscopy and hysteroscopy with curettage.

Reference:

• 1) Prescriber (2004); 15 (10):42-50.
• 2) Wong CL et al.Oral contraceptive pill for primary dysmenorrhoea. Cochrane Database Syst Rev. 2009 Oct 7;(4):CD002120.