It is not safe to mix cocaine with most drugs, especially other stimulants. The latter can place an extreme amount of strain on the heart and can even cause death. Depressants can be dangerous as well. One of the most popular cocaine combinations is called a 'speedball'. This is a mixture of heroin and speed. It is extremely powerful and quite dangerous. People die from taking speedballs all of the time. Jim Belushi, a very famous comedian and musician died before his time after taking a speed ball. Mixing stimulants and depressants can be very hard on the heart and may even cause it to get off rhythm. This is quite dangerous and may result in death.

Common Cocaine Combinations

Cocaine and alcohol: Mixing these substances together is quite dangerous. When they are consumed at the same time, a chemical called cocaethylene is created. If a person combines these two drugs regularly, they face the risk of it building up in the liver. This is quite toxic and can damage the liver, which can obviously be very harmful. Another related danger of mixing the two is the effect on the heart. People who have cocaehtylene in their systems are at an increased risk of having a heart attack in their 30s and 40s. 

Cocaine and amphetamine: Both cocaine and amphetamines are stimulants. Consequently, they have a similar affect on the body. Both place considerable strain on the heart. Individuals are at increased risk of dying via a heart attack. Mixing the two drugs together can also result in a high level of toxicity.

Cocaine and marijuana: Individuals who use marijuana often report that it helps them relax. When taken with cocaine, it can help take the edge off. Some people may mix the two for this purpose.

Cocaine is a very powerful stimulant. When taken alone it places a considerable amount of stress on the heart. When it is combined with other drugs, these effects can be multiplied or prove toxic. Some drugs, particularly marijuana, may take the edge off.  As with all drugs, mixing can be extremely dangerous and should be avoided. The nature of drugs is that they are unpredictable. When they are mixed together the results can prove disastrous.