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Pamela Mason is a freelance pharmaceutical journalist based in Wales |
At time to time during your student days and over the Christmas period, you may find yourself suffering from the after effects of drinking too much alcohol — a hangover. Having a hangover means suffering from a combination of any of the following symptoms after drinking alcohol:
• Headache
• Nausea or vomiting, or both
• Mild diarrhoea
• Tremor
• Red eyes
• Thirst
• Generally feeling unwell
• Sensitivity to light and noise
• Hot flushes
• Aching muscles
• Dizziness
• Fatigue
• Feeling depressed or irritable
• Poor concentration and memory
• Impaired visual spatial skills
Hangovers can have serious consequences in terms of safety (eg, driving skills can be impaired even when blood alcohol levels have fallen below 80mg/100ml — the legal limit for driving).
What causes a hangover?
Alcohol depresses the central nervous system so that co-ordination, memory and judgement are impaired and vision and hearing are distorted. Other effects of alcohol include
vasodilation and reduced blood glucose. However, the causes of alcohol hangovers are not fully understood. Several culprits, such as dehydration and acetaldehyde, have been
suggested. The sleep disturbances associated with excessive drinking can also contribute to a hangover.
Dehydration Alcohol acts as a diuretic (it inhibits the effect of antidiuretic hormone on the kidneys) so drinking too much of it causes dehydration. This, in turn, can result in many hangover symptoms, including headache and thirst.
Acetaldehyde Acetaldehyde is the main metabolic product of ethanol. It can cause flushing, a throbbing headache, palpitations and nausea, as well as a host of other symptoms. It is on this basis that disulfiram (Antabuse) is used to treat alcohol dependence — disulfiram blocks the oxidation pathway so acetaldehyde accumulates.
Congeners The severity of hangovers appears, in part, to be determined by the concentration of congeners in the drink consumed. Congeners include substances such as amyl alcohol, butyl alcohol, methyl alcohol, propyl alcohol and isopropyl alcohol. They are present as impurities in most drinks to varying degrees, but they also give drinks flavour, smell and colour. Vodka, gin and other clear alcoholic drinks are generally lower in congeners than darkly coloured drinks (eg, whisky, port, brandy, bourbon, red wine) because of the filtering and distillation processes involved in making them, and are, therefore, associated with less intense hangovers.
What are the cures?
Not surprisingly, there is an enormous variety of “hangover cures”. Perhaps the best known is “hair of the dog”, which involves drinking more alcohol. This is supposed to alleviate the withdrawal symptoms of an alcohol overdose, but the effects are temporary and the hangover has to be faced at some time. Some say that cocktails like a Bloody Mary are great restoratives but this behaviour should not be encouraged because it can lead to alcohol abuse.
Other remedies advocated by drinkers include blended recipes containing ingredients such as cabbage, bananas, eggs, honey, olive oil, lemon juice, tomato ketchup, Tabasco sauce and Worcester sauce. Drinking caffeinated drinks or eating cold pizza, yeast spread on toast or dry toast on its own are other common suggestions. There is no hard evidence that any of these help. Isotonic drinks have also been recommended to achieve quick rehydration.
Over-the-counter products A number of over-the-counter medicines are frequently used to alleviate hangovers. Some, such as Alka-Seltzer, Andrews Plus and Resolve, are marketed as stomach settlers and not specifically for hangovers. They contain an analgesic together with antacids (usually carbonates and bicarbonates), and dissolve in water to produce a fizzy drink. Anecdotally, they help some people, although hangover sufferers may not welcome the bloated feeling from a carbonated drink. In any case, if the person has nausea or vomiting he or she may be unable to keep anything down.
Analgesics, such as aspirin, ibuprofen and paracetamol, are frequently used to treat hangovers, but whether they are effective is debatable. Products containing paracetamol might be preferable because aspirin can further irritate a delicate (and empty) stomach.
Eye drops containing naphazoline can be recommended for red eyes.
Preventing hangovers
Unfortunately, the best advice for preventing a hangover is not to drink alcohol at all or to drink it in moderation. However, such advice usually falls on deaf ears, particularly where students are concerned. Tips for reducing the severity of a hangover include drinking slowly (one drink per hour), alternating alcoholic drinks with non-alcoholic ones, eating a meal before consuming alcohol, drinking plenty of water before going to bed and avoiding drinks that contain congeners.
A recent review1 found that taking tolfenamic acid on the night of alcohol consumption was associated with a small improvement in hangover symptoms. The following morning, participants who received tolfenamic acid reported less headache, nausea, vomiting and thirst. Other non-steroidal anti-inflammatory drugs, including aspirin and ibuprofen, have not been studied for this indication.
In fact, few trials on treating hangover symptoms have been conducted and the number of subjects is usually small.
Complementary remedies A variety of complementary remedies and nutritional supplements containing sugars, succinic acid, fumaric acid, L-glutamine, herbs (eg, milk thistle, artichoke) charcoal, calcium carbonate, vitamins and minerals are marketed as hangover cures. Examples of such products include Chaser, Hangover-Over!, Rebound, RU21 and Russia Party. Some of these are only available on the internet. Usually, a dose is taken with the first drink, repeating the dose after a specified number of drinks.
The rationale for the inclusion of many of these substances (eg, dextrose, succinic acid, fumaric acid, L-glutamine) is that they either inhibit the formation of acetaldehyde or they accelerate its metabolism and removal from the blood stream. Sugars are also added in an attempt to limit the blood glucose lowering effect of alcohol. Charcoal is believed to absorb congeners.
Herbal ingredients such as artichoke and milk thistle are included on the basis that they can help to detoxify the liver. B vitamins and vitamin C are lost through diuresis — the reason for their inclusion.
Whether these products work is debatable. Product websites contain testimonies of benefit, but evidence from clinical trials regarding the efficacy of these remedies is limited.
A recent review summarised evidence from randomised controlled trials for gamma-linolenic acid from Borago officinalis (borage), Cyanara scolymus (artichoke), Opuntia ficus indica (prickly pear cactus) and yeast.2 Borage, prickly pear cactus and yeast were associated with some benefit in hangover symptoms, although artichoke did not seem to be effective. The reviewers stated that the results with O ficus indica were not as positive as they appeared in the original paper which, for example, included the risk of a severe hangover being halved. There was no significant difference in mean overall hangover symptom index between the treated and placebo groups.
Vitamin B6 In one placebo-controlled cross-over trial, (n=17), participants given 1,200mg of vitamin B6 in three divided doses experienced 50 per cent less severe hangover symptoms than those given a placebo. However, the safe upper level for vitamin B6 recommended by the Food Standards Agency is 10mg per day for long-term use.
A report on the safe upper levels for vitamins and minerals by the FSA’s expert group on vitamins and minerals states that large doses of pyridoxine (usually quoted as over 2,000mg per day) can cause nerve damage. In addition, the report states that long-term use of vitamin B6 (generally in excess of 200mg daily) has been reported to result in paraesthesiae (tingling hands and feet), somnolence and low serum folic acid levels. The side effects of taking 1,200mg occasionally are uncertain so this should not be recommended.
Conclusion
There are many hangover cures, both old and new, but the only evidence-based cure is time and rest.
References
1. Wiese J, Shilpak MG, Browner WS. The alcohol hangover. Annals of Internal Medicine 2000;132:897–902.
2. Pittler MH. Complementary therapies for alcohol hangovers. Focus on Alternative and Complementary Therapies 2004;9:265–8. |
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