If the white blood cells are severely damaged as a side effect of a drug, as a result, the body's immune system may collapse. This means that both bacterial and viral infections open the door, which in extreme cases can have fatal consequences. One then speaks of an agranulocytosis.

What is an agranulocytosis?

An agranulocytosis is referred to when the proportion of granulocytes falls below 500 cells per microliter of blood. Granulocytes belong to the white blood cells.

An agranulocytosis is referred to when the proportion of granulocytes falls below 500 cells per microliter of blood.

Granulocytes belong to the white blood cells and can be found wherever the body comes into contact with pathogens, for example on the mucous membranes. They are formed in the bone marrow and are mainly responsible for the defense against bacteria and fungi, so crucial for the maintenance of the immune system.

If no granulocytes are formed in the bone marrow, for example, as a result of taking a drug, there is a strong reduction or even complete absence of granulocytes in the blood.

Forms of agranulocytosis:

Generally, a distinction is made between allergic and congenital agranulocytosis. Congenital agranulocytosis is rare. An example here can be called the Kostmann syndrome.

More common, however, is drug-induced agranulocytosis, with two types being distinguished. Type I allergic agranulocytosis is triggered by drugs. The immune reaction to the drug, in which the granulocytes are damaged, happens both time- and dose-independent.

Type II is also called toxic agranulocytosis because the drug triggers toxic bone marrow damage. Characteristic here is that type II is both dose-dependent and time-dependent. The difference between type I and type II is that granulocytes are formed in type I, but they are destroyed. Type II already prevents the production of granulocytes in the bone marrow.


Unless it is a hereditary conditional agranulocytosis, agranulocytosis can be triggered by an immune reaction to certain drugs as well as toxic effects on the bone marrow.

The most common cause of agranulocytosis is the intolerance of certain drugs that severely damage the granulocytes. Medications in which agranulocytosis has been frequently observed are:

  • Analgesics, eg metamizole, paracetamol
  • Antipyretics, eg phenylbutazone
  • Antibiotics, eg metronidazole, penicillin
  • Neuroleptics, psychotropic drugs
  • Antithyroid drugs, eg thiamazole, carbimazole
  • sulfonamides
  • Others, eg antihistamines, antidiabetics

Drugs that trigger type II agranulocytosis directly damage bone marrow cells. An example of such a drug is chlorpromazine. It should be noted that the drug inducing agranulocytosis can be re-used over time at a correspondingly low dose without causing such a reaction. Unlike the type I. Here, the allergic reaction usually stays alive for a lifetime and even the smallest amounts of the drug again lead to an agranulocytosis.

Symptoms, complaints & signs

An agranulocytosis first expresses itself by non-specific symptoms. At the beginning of the disease headache and muscle pain, fever and a general malaise occur. In the further course it can come to high fever with shivering and gastrointestinal complaints. Nausea and vomiting are typical, and diarrhea usually occurs in later stages.

Loss of fluids can lead to deficiency symptoms, such as dizziness, tiredness and limited physical and mental performance. Furthermore, agranulocytosis can cause lymphadenopathy, mucous membrane necrosis in the mouth and throat, and respiratory tract infections. The anus area can also inflame, which is manifested by severe pain, itching and bleeding.

The weakened immune system can no longer ward off any pathogens, which leads to increased infections. Especially the mucous membranes are affected - it comes to about herpes or tonsillitis. If the agranulocytosis is based on an immune reaction to a drug, the symptoms mentioned occur immediately after ingestion.

On the other hand, toxic agranulocytosis progresses creepingly, causing major symptoms only in the later stages of the disease. An external feature of the sufferer is pale skin, which is sometimes associated with sweating and skin irritation.

Diagnosis & History

The onset of agranulocytosis manifests itself for the time being nonspecifically with a general malaise, head and muscle pain and fever. This is followed by a high fever with chills, nausea, lymphadenopathy, mucosal necrosis of the mouth and throat, infections of the respiratory tract and the anus area. Also pneumonia or diarrhea can occur. Generally, there is a serious feeling of illness.

As the immune system collapses, infections, especially of the mucous membranes, occur in particular. Examples are herpes or tonsillitis.

If it is an immune reaction to a drug, the symptoms occur immediately, often after the first dose. In the case of toxic agranulocytosis, the first symptoms can only become apparent after weeks.

The question whether an agranulocytosis is present or not can be answered very simply by examining the granulocytes in the blood (blood count).

In addition, a physical examination is carried out, in which lymph nodes and mucous membranes are examined in detail.

The course of the disease as well as the medication intake are worked on with the patient. There are no methods that could detect the causative drug. Therefore, it must be determined thoroughly, which drug comes as a trigger in question.

Another possibility for the diagnosis of agranulocytosis is the bone marrow biopsy, in which samples of the bone marrow are removed and examined by means of a needle.


Agranulocytosis is an allergic intolerance to certain medications. It acts directly in the bone marrow and causes an acute lack of granulocytes. These white blood cells are in fact the police of the body and have the property of destroying pathogens as well as fungi, parasites and bacteria.

If this body's defenses are eliminated, serious complications are the result. The symptom is considered a side effect of drugs such as: antibiotics, analgesics, neuroleptics, antithyroid drugs and cytotoxic drugs. Patients whose physical condition worsens when taking prescribed medicines require medical assistance.

In the worst case, a mucous membrane necrosis or life-threatening toxic reaction threatens. The thorough anamnesis can analyze the sensitivity but not cure it. If patients are subject to long-term medication that causes agranulocytosis, they are subject to regular medical supervision.

In addition to the diagnosis, an attempt is made to stabilize the immune balance of the patient. In some cases, the affected person is isolated, as long as there are already symptoms of fever and the lymph nodes are swollen. To restore the physical balance, a broad-spectrum antibiotic is served.

Depending on the condition, the person concerned is given an indication of granulocyte growth factors. In order to minimize the risk of complications, agranulocytosis patients should pay attention to the accurate hygiene of all body orifices in addition to the therapy. Due to the increased risk of infection are places where crowds close together to be avoided.

When should you go to the doctor?

In any case, the agranulocytosis must be examined and treated by a doctor. If it does not come to a treatment, then it can come in the worst case to the death of the patient. For this reason, a weakened immune system must definitely be treated and strengthened again. The person concerned should then consult a doctor if it comes to fever and a general fatigue. This may indicate agranulocytosis. Not infrequently, there is also a bad and foul-mouthed bad breath and a very strong headache.

These symptoms may also indicate the disease. If the visit to the doctor is not possible, then an emergency physician can be called, for example, if it comes to breathing difficulties or a loss of consciousness of the patient. Furthermore, pneumonia can also be a symptom of agranulocytosis. The treatment can usually be done by a general practitioner.

Should it come to further complaints, they can be treated by a specialist physician. As a rule, agranulocytosis does not lead to a reduced life expectancy. A doctor must also be consulted if the agranulocytosis is triggered by a particular drug. The discontinuation or modification of the drug should, however, only after consultation with the doctor.

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Treatment & Therapy

If agranulocytosis is suspected, the triggering drug must be discontinued immediately. If it is unclear which drug is used in this particular case, stop taking all medications that are not essential. The production and number of granulocytes in the blood then increases again and regulates. Growth can be supported by the administration of granulocyte growth factors.

In order to help the body's own defense system, in the case of infections and fever the use of antibiotics is provided. The rapid administration of a broad-spectrum antibiotic can usually prevent a fatal effect of the disease caused by a sepsis.

If severe symptoms occur, it is necessary to stay in a hospital. In order to minimize the risk of infection, isolation of the affected person makes sense. In general, one has to pay attention to a special body hygiene and avoid crowds because of the increased infection possibilities.

Since agranulocytosis is a rare disease, many doctors and pharmacists underestimate the risk. Since some triggering medications are used in the initial flu-like symptoms of agranulocytosis, a downward spiral may be produced when administered.

Therefore, if the symptoms listed above occur, be sure to consult a doctor rather than treat the symptoms with self-medication or by the pharmacist by selling a flu remedy. In case of missing or delayed diagnosis by the doctor, the diseases caused by an agranulocytosis can have a life-threatening effect.

Outlook & Forecast

Agranulocytosis can be well treated if detected early. However, the symptoms such as fever, nausea, chills, malaise and loss of appetite are so unspecific that the critical death of granulocytes as part of leukocytes is often not detected in time. Rather, other causes of these symptoms are often initially suspected.

Patients taking medications such as certain neuroleptics or analgesics are potentially at risk. If the symptoms of prolonged influenza are found in people who have been affected by influenza, leukocytes should be measured in the blood. If their number reaches a critical lower limit, agranulocytosis is present. This can lead to complete breakdown of the immune system and be fatal. However, agranulocytosis is rare.

Therapeutically, all medications that can trigger agranulocytosis are first discontinued. The number of leukocytes then rises quickly. In addition, drugs are used, which temporarily take over the functions of the immune system until it has stabilized again. The chances of recovery are good then.

Since the symptoms of agranulocytosis are so unspecific, patients taking medications such as the neuroleptic clozapine should go to the blood control regularly. If the number of leucocytes continuously checked, can be intervened quickly. Left untreated, agranulocytosis is very difficult in most cases.


It is important to remember the problem of self-medication. Ingestion of medicines in their own right can lead to serious illness in case of hypersensitivity to any of the ingredients. Therefore, any medication should be discussed in advance with a doctor.

If drugs that induce agranulocytosis are administered, a regular check on the person's blood can prevent serious consequences.

When an agranulocytosis is present, particular attention must be paid to appropriate personal hygiene, especially in the areas of the mouth, throat and anal region, in order to prevent any risk of infection.


As a rule, the options for aftercare for agranulocytosis are severely limited. The patient is always dependent on medical treatment. Without treatment it can come in the worst case also to the death of the person concerned. An early diagnosis and treatment always have a very positive effect on the further course of the disease and can prevent further complications.

The patient is dependent on medication for agranulocytosis. These should be taken regularly. Likewise, possible interactions with other drugs should be considered. Parents must also pay attention to their children taking regular medication. However, if the agranulocytosis shows severe symptoms, it is necessary to stay in a hospital.

The person concerned should be careful to look after themselves, so as not to burden the immune system unnecessarily. For example, the person concerned should not be in risky areas. In general, a healthy lifestyle also has a positive effect on the course of agranulocytosis. Above all, a healthy diet and the absence of nicotine and alcohol can relieve the symptoms. Furthermore, contact with other persons affected by agranulocytosis is also recommended.

You can do that yourself

In the case of agranulocytosis, the most important self-help measure is to carefully observe the effect of the prescribed medication and to communicate the results to the responsible family doctor or cardiologist. Often, switching to another drug will be enough to correct the decline in granulocytes. Occasionally, however, side effects and interactions occur, which can lead to other complaints.

Patients should also pay attention to a healthy diet that supports the production of white blood cells. Foods that are rich in vitamin B12 and folic acid, such as bananas, nuts and low-fat fish, have proven particularly useful. An adapted diet and medication is usually sufficient to reduce and eventually eliminate the agranulocytosis.

Since the suffering may also cause physical and mental discomfort, depending on the symptom picture, further therapeutic measures may be necessary, which the patient can often support through rest and protection. The most important self-help measure in an agranulocytosis is to pay attention to the body's own signals. If there is another lack of granulocytes, such as tiredness or fatigue, a visit to a doctor is recommended.

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