Leg cramps are defined as sudden, involuntary and painful muscle spasm, which usually affect calf, but may also affect foot or thigh (NICE, 2018). Leg cramps which happen at night (nocturnal leg cramps) are a common condition, with increased occurrence among the elderly population (ibid). This post summarises the use of quinine for leg cramps. In summary, I will discuss the following:
- causes and symptoms of leg cramps
- treatment recommendations for leg cramps – how leg cramps are treated in the NHS
- how to get quinine in the UK,
- effectiveness of quinine in the reduction of leg cramps
- quinine – possible side effects
- use of tonic water for leg cramps
- an alternative options for management of leg cramps
Causes of leg cramps
In most cases, leg cramps which happen at night have an unknown cause; however, cramps may be caused by an underlying condition. Patients who experience muscle cramps, which affect their sleep and are of unknown cause may speak to their GP to get advice and possible treatment. GP will perform examination and history to check if any underlying conditions may cause cramps, for example, dystonia (involuntary muscle contractions), myoclonus (involuntary muscle movement), lower motor neuron (LMN) syndrome and other conditions or medications.
A detailed investigation is usually not needed unless cramps are characterised by unusual features. In this case, a GP may recommend a blood test to check various electrolytes, urea, calcium, kidney and liver functions, glucose and thyroid function tests.
Leg cramps are characterised by sudden onset of painful muscle spasm affecting calf, sometimes foot and rarely tight. Pain can last a few second to less than 10 minutes. Nocturnal leg cramps usually affect a single muscle with a visible tightening of the muscle.
The recommended treatment of leg cramps
Patients are usually reassured by their doctor that muscle cramps are common, and in most cases the cause is unknown. Self-care advice typically includes massages and stretching of the affected area (muscles), possibly to reduce the number of attacks.
Stretching exercises for leg cramps
Patients who experience post-cramp pain are usually recommended to use simple analgesics, such as paracetamol or ibuprofen or both drugs together.
Quinine for leg cramps: treatment recommendations
Quinine is not usually recommended for treatment of leg cramps of unknown reason. People who experience excruciating leg crams regularly and who tried self-measures without success may be recommended quinine for leg cramps temporarily (to see if the treatment makes any difference).
If appropriate, a recommended 4-week trial with quinine for leg cramps is commenced.
Quinine for leg cramps: a recommended dose
The recommended daily dose for quinine in the treatment of leg cramps is 200mg-300mg of quinine before going to bed.
The treatment is stopped if no improvement in symptom control is achieved during four weeks of the treatment. Patients who benefit from taking quinine will continue to take it for three months with GP reviews to follow every three months.
How to get quinine for leg cramps?
In the UK, quinine is only available as a prescription-only medication. A qualified prescriber needs to produce a prescription for quinine so that it can be supplied in the pharmacy. A qualified prescriber would normally be a GP, who can produce NHS prescription. Alternatively, patients may see a private doctor, who would issue a private prescription if the treatment is recommended.
In the UK quinine is licensed for leg crams (nocturnal) and treatment of some forms of malaria.
National Institute for Health and Care Excellence (NICE), which sets recommendations for treatment of diseases in the UK does not recommend quinine for leg cramps ‘due to the poor benefit-to-risk ratio’ (NICE, 2018) unless:
- leg cramps affect patients sleep
- leg cramps are very painful and frequent
- self-measures fail to give any improvement of symptoms and their frequency
Quinine: available forms
Quinine comes in the form of tablets in the following drugs:
- Quinine sulfate 200mg tablets
- Quinine sulfate 300mg tablets
- Quinine bisulfate 300mg tablets
Is quinine effective in reducing leg cramps?
The best evidence for the effectiveness of quinine in leg cramps come from the review produced by Cochrane (a global group of scientists). Cochrane looked at all available clinical trials (the study of the safety and effectiveness of drugs) and identified 23 studies with a total of 1586 participants who took quinine for leg cramps (daily dose: 200 mg to 500 mg).
Over half of participants came from just five studies, which compared quinine with placebo (a dummy pill) or vitamin E, or a quinine‐theophylline or xylocaine injections into the calf muscle.
Overall the quality of clinical trials was described as low, due to risk of bias in all studies.
Nevertheless, the main conclusions from Cochrane’s review were as follows:
- When compared to a placebo pill (a dummy pill), quinine significantly reduced the number of cramps over two weeks
- Cramp intensity was reduced
- The number of ‘cramp’ days were reduced
- Cramp duration was not affected by taking quinine.
When compared with a placebo pill, people who took quinine experienced a greater number of side effects, mainly of gastrointestinal nature.
Quinine sulfate: possible side effects
There are no specific common side effects listed for quinine sulfate – the most prescribed medication for leg cramps. Patients are advised to contact their GP urgently if the following side effects occur:
- Allergic reactions characterised by itchy skin, swelling of the throat, lips or tongue
- Soreness of the mouth, eyes, nose, skin rash and blistering (a possible sign of Stevens-Johnson syndrome
- Cinchonism (usually caused by an overdose of quinine) with symptoms of abdominal pain, diarrhoea, and changes to the vision, for example, blurred vision, headaches, feeling or being sick, irregular heartbeats.
- Bruising or bleeding more easily, including nose bleeds, increased number of sore throat or other infection episodes.
In the event of overdose, quinine is toxic and can cause life-threatening side effects. Please refer to product information leaflet for more information on side effects.
Can tonic water help with leg cramps?
Tonic water contains quinine; however, there is a limit on how much quinine can be included in tonic water. For example, in the US, tonic water can contain no more than 83mg or quinine per 1 litre of tonic water (Govinfo, N.D).
With the recommended dose of 200-300mg of quinine sulphate for the treatment of leg cramps, it would be impossible and not recommended to consume around 3L of tonic water daily.
Alternative products for leg cramps
There are a number of over the counter supplements which claim to help with leg cramps. I will review the most popular supplements/products for muscle cramps as found on Amazon.co.uk and other online websites and outlets.
Magnesium for leg cramps
Magnesium has been studied as a potential candidate for muscle cramps. Magnesium supplements are available from supermarkets, pharmacies and online websites, some of them in combination with other vitamins and mineral. Yet again, Cochrane looked for good quality evidence behind the use of magnesium supplements in muscle cramps. In total, seven studies were reviewed, four in the elderly population and three studies in pregnant women.
Four studies on magnesium use in leg cramps in an elderly population found no benefit on reducing the episodes of cramps or their severity; however, a total number of participants in all four studies was 322 people. Two out of three studies which looked at the use of magnesium in pregnancy showed no benefit in cramps reduction in pregnancy. In contrast, one study reported both the reduction of episodes and severity of cramps. Overall, Cochrane concluded more research is needed to confirm any benefits on the use of magnesium in pregnancy-related cramps.
High Absorption Magnesium as for Leg Cramps (Quinine alternative)
High Absorption Magnesium for Leg Cramps and Sore Muscles, Restless Leg Syndrome Relief (RLS), Muscle Relaxer (MgSport) which is available on Amazon.co.uk, contains a combination of:
- Vitamin B6
- Vitamin D
- Vitamin E
This food supplement is advertised (perhaps slightly over the top) as a ‘miracle’ supplement due to magnesium content and unique vitamin combination, which is only found in this product on the market. Vitamins found in Magnesium (MgSport) supplement assist with muscle spasms, restless leg syndrome and cramps.
Leaving aside marketing on the ‘tin’, Magnesium (MgSport) is Amazon’s Choice (well-priced product with high rates) and overall has a majority of positive reviews. Despite its high price, some may find this product beneficial.
It is possible to buy magnesium on its own. Lindens Magnesium (pack of 90, 500mg tablets) is a best selling magnesium product on Amazon.co.uk. Lindens Magnesium is a supplement sold to improve muscle function and reduction of tiredness & fatigue. With hundreds of reviews, this product has many positive comments about possible benefits in muscle cramps and restless leg syndrome.
NO CRAMPS for leg cramps (contains quinine extract)
NO CRAMPS (STC nutrition) is a French-made product, which can be purchased on Amazon.co.uk Despite the lack of English description, this product sells on Amazon.co.uk, perhaps due to its “interesting” combination of ingredients. NO CRAMP contains:
- Vitamin B6
- Ginseng (to help with fatigue)
- Arnica (aromatic extract)
- Quinquina (extract of quinine from Cinchona pubescens) 50mg per tablet.
It seems that this is the only supplement available on Amazon.co.uk, which contains quinine extract from the plant and additionally magnesium and Vitamin B6.
A possible benefit of magnesium on muscle crams was discussed in the previous paragraph. Regarding the rest of the ingredients found in NO CRAMPS, there is no evidence to suggest they reduce muscle cramps. This, of course, does not mean simply that the product does not work.
Crampex: what happened to Crampex?
Crampex was the only over the counter medicine licensed for night muscle cramps. Crampex contained the following:
- Cholecalciferol 0.02 mg – Vitamin D3
- Calcium Gluconate 200 mg – Calcium
- Nicotinic Acid 20mg – Vitamin B3
Crampex has been withdrawn from the market around 2016, and it has not been back since. Three active ingredients found in Crampex – Vitamin D3, Vitamin B3 and calcium are available as separate supplements from a variety of places including Amazon.co.uk
In the UK, quinine can be prescribed on a trial basis to see if the treatment reduces nocturnal leg cramps frequency and severity. Patients who experience muscle cramps at night, which affect their sleep or have other symptoms (for example, swelling numbness of their legs) should speak to their GP.
Several supplements containing magnesium and other vitamins are available in supermarkets, pharmacies and online, although their benefits in muscle cramp reduction are not clear or not fully investigated.
Govinfo (ND) Quinine – limitation. Available at: https://www.govinfo.gov/content/pkg/CFR-2008-title21-vol3/pdf/CFR-2008-title21-vol3-sec172-575.pdf Accessed on 16/08/2020
NICE (2018). Leg cramps. Available at: https://cks.nice.org.uk/topics/leg-cramps/ Accessed on 17/08/2020