Healthy Living

What Is a GI Cocktail?

A GI cocktail, sometimes known as "green lizard" or "green goddess" is used to treat dyspepsia.

What Is a GI Cocktail?


A GI cocktail or gastrointestinal cocktail is a mixture of liquid antacid, viscous lidocaine, and an anticholinergic agent. A GI cocktail is primarily used to treat dyspepsia.

There are a wide variety of GI cocktail recipes nowadays. One popular recipe is a mixture of viscous lidocaine, Maalox, and Donnatal in a mixture of 10-30 ml Mylanta, 10 ml viscous lidocaine, and 10 ml of Donnatal. This mixture is also called "green lizard" or "green goddess".

Due to the varied mechanisms of relief, the efficacy of this mixture is considered far more superior than taking only one of its components. However, according to a recent study, it has been found that an antacid alone can relieve stomach pain when compared to a GI cocktail.

A GI cocktail contains the following ingredients: 

1. Antacid

An antacid neutralizes stomach acidity and relieves indigestion, heartburn, and an upset stomach. These are available over-the-counter, and it is taken by mouth and used for the relief of minor symptoms. Antacids are acid-reducing drugs. The type of bacteria that causes ulcers are not killed by antacids.

If the antacid contains magnesium, it may cause diarrhea. On the other hand, if it contains calcium and aluminum, it may cause constipation. Kidney stones may be caused by the long-term use of antacids. When too much acid is produced, it can damage the lining of the stomach. Antacids tend to relieve pain and reduce damage to the stomach since it chemically neutralizes gastric acid through its alkaline ions.

2. Lidocaine

Lidocaine is a numbing medication used to:

  • Numb tissues in a specific area
  • Perform nerve blocks
  • Treat ventricular tachycardia
  • Decrease bleeding
  • Mixed with adrenaline

There are some side effects associated with the use of lidocaine and they include:

  • Muscle twitching
  • Changes in vision
  • Sleepiness
  • Tingling or numbness
  • Vomiting
  • Irregular heart rate
  • Low blood pressure

3. Anticholinergic Drug

It blocks the neurotransmitter called acetylcholine in the central and peripheral nervous system. It inhibits parasympathetic nerve impulses by selectively blocking the binding of acetylcholine to its nerve cell receptors. 

These nerve fibers are responsible for the involuntary movement of the smooth muscles. They control the nerve fibers of the gastrointestinal tract as well. They are used to treat gastrointestinal disorders such as diarrhea, peptic ulcer, diverticulitis, pylorospasm, ulcerative colitis, vomiting, and nausea.

Using GI Cocktail to Identify Cardiac vs. Noncardiac Chest Pain

It is difficult to distinguish between ischemic chest pain and gastroesophageal pain since they both share almost similar characteristics. They include dyspepsia and response to nitrate. However, the only difference is one can end up in an Emergency Room (ER) and the other one will not. In an attempt to make a differentiation in the ER, sometimes, a GI cocktail can be used. The composition of a GI cocktail may vary, but it usually consists of a mixture of viscous lidocaine, liquid antacid, and liquid anticholinergic/barbiturate compound.

In the 1970s, a small study was done to differentiate ischemic chest pain from gastroesophageal pain, and the administration of a GI cocktail was highly reliable. Sixty patients were treated with 20 ml viscous lidocaine. These patients presented chest pain, epigastric pain, or both. Myocardial ischemia was not found in patients who achieved significant pain relief from the GI cocktail. Myocardial ischemia or acute MI was diagnosed to those who did not respond to the GI cocktail. However, apart from few research studies, the literature is sparse on the use of GI cocktail when it comes to evaluating chest pain.

There is a clear limitation on the research regarding GI cocktail being used as a diagnostic test for the evaluation of chest pain. Since a GI cocktail can be administered soon before or after giving potential pain relievers, the interpretation of the test can be difficult.

Pain Relief

Pain relief in the acute settings is typically obtained with opioid analgesics such as fentanyl or morphine sulfate. In patients with biliary and renal colic, pain relief can be achieved when ketorolac IV is combined with narcotic agents. For the treatment of undifferentiated abdominal pain, ketorolac is not recommended as abdominal findings may be masked by it and could increase the bleeding time. A GI cocktail can provide relief to patients with epigastric discomfort. 

Often, a GI cocktail is used as a diagnostic maneuver. However, a GI cocktail cannot be recommended for the routine evaluation of chest pain since there is a possibility of spontaneous and coincidental resolution of ischemic chest pain due to a variety of medications given. However, if a patient presents symptoms that strongly suggest a gastrointestinal origin, then pain can be relieved by antacids or a GI cocktail.  

Treating an abdominal pain is as important as treating the associated symptoms of the patient. A GI cocktail, apart from being a common analgesic, is also used for the treatment of epigastric pain or dyspepsia. The contents and combinations of GI cocktail are often studied. The following comparisons are generally studied:

  • Different combinations of antacids
  • Antacid and belladonna alkaloid combination, which includes hyoscyamine, atropine, scopolamine, and phenobarbital
  • Antacid, viscous lidocaine, and belladonna alkaloid combination, which include hyoscyamine, atropine, scopolamine, and phenobarbital

Among the treatment groups, the above comparative study did not find any significant difference when it comes to pain improvement. This study was in contrast to another study, in which after receiving an antacid along with viscous lidocaine, showed pain improvement compared to those who only received an antacid. 

Statistically, significant improvement in pain is shown when treatment is given with viscous analgesic whether it is lidocaine or benzocaine. Relief from a GI cocktail alone was obtained by 34 patients who presented chest pain and abdominal pain. Thus, making this medicine in the treatment of epigastric pain is a useful adjunct.   

The use of GI cocktail to differentiate the types of pain has not yet been supported by any recent literature. However, the practice still continues. Physicians believe that esophagitis or gastritis causes a burning substernal pain that is relieved by antacids. Studies have shown that pain, which is described as indigestion or chest pain may be an indicator of chest pressure or ischemia. 

There is a questionable diagnostic value suggested by the existing literature. Usually, just a few minutes after the administration of active medications such as antiemetics, narcotics, nitroglycerin, ketorolac, and histamine blockers, a GI cocktail is administered. Thus, the interpretation of the test result is clouded.

Another limitation is the absorption of viscous lidocaine and instances of toxicity and seizures have occurred even though the patients have levels below 1 µg/ml. The usual therapeutic level is 2-5 µg/ml. Moreover, there are many examples that have been documented, wherein a GI cocktail relieves the discomfort of other health issues such as myocardial infarction, pancreatitis, cholecystitis, and hepatitis.

A GI cocktail is usually a mixture given to patients with symptoms of dyspepsia in the emergency department. It is mixed using few combinations. There was one study done in which it was found that adding of Donnatal or Donnatal with lidocaine to an antacid may not relieve dyspepsia compared to a plain antacid. Thus, the concoction of a GI cocktail may not be necessary.

Overindulgence of GI Cocktail

In emergency care, a GI cocktail is frequently used to separate ischemic pain from dyspepsia. The theory is that a patient does not have a heart attack if the pain is relieved after taking a GI cocktail. However, it was found in a three-month study that the GI cocktail was given too freely. In a study of 97 patients who are given a GI cocktail, 40 of them presented chest pain and 49 presented abdominal pain. The rest presented complaints of anxiety, nausea, and breathlessness. The GI cocktail was indiscriminately given for the following conditions:

The GI cocktail was also often administered with other drugs such as nitroglycerin and narcotics. Sixty-eight patients were relieved from their symptoms. They were thought to obtain relief due to the GI cocktail but they were also given another medication. Eight out of 11 patients who were admitted with a possible myocardial infarction received a GI cocktail with partial or complete symptomatic relief. Within one day, two of them who obtained complete symptomatic relief went on to have percutaneous transluminal coronary angioplasty.  

Hence, clinicians recommend that a GI cocktail should be used wisely and when it is being administered, the reasons for its use should be clearly documented. At this time, it should be made sure that for around 15-30 minutes, no other medication is given to help determine whether the GI cocktail is working or not. Moreover, doctors recommend the recording of GI cocktail effects and the time taken to achieve relief from the symptoms to determine whether the relief was a complete or partial one.

According to some studies, to make a GI cocktail, the addition of lidocaine and sometimes Donnatal could increase the efficacy of the treatment. Since both agents are well tolerated, the risks associated with their addition is low and the cost also is minimal. However, with every drug, there is a possibility of risk and cost. It is added up substantially by the frequency with which the cocktail is used. It has been recommended that for the treatment of dyspepsia, antacids should be used alone.