"Mannitol" and "glycerol fructose" are both commonly used drugs for lowering intracranial pressure. What are the differences?

*For medical professionals' reference only, read these 3 points to know! Intracranial pressure (ICP) refers to the pressure generated by the contents of the cranial cavity on the wall of the cranial cavity, also known as cerebral pressure.

Normal intracranial pressure is 0.
7~2.
0kPa (5~15mmHg) for adults and 0.
5~1.
0kPa (3.
5~7.
5mmHg) for children in the lateral position.

The common causes of increased intracranial pressure are: head injury, intracranial space-occupying lesions, cerebrovascular disease, intracranial inflammation and so on.

At present, the commonly used clinical drugs for lowering intracranial pressure are mannitol, glycerol fructose, diuretics, hormones, etc.
[1].

Among them, mannitol and glycerol fructose are most widely used clinically.

So, what are the similarities and differences in their clinical features? 01 Pharmacological effects Table 1: The pharmacological effects of mannitol and glycerol fructose.
It can be seen from the above table that both are approved for increased intracranial pressure and cerebral edema.
The pharmacological effects of the two are similar, and both are hypertonic solutes and diuretic Dehydrating agent.

The osmotic pressure of plasma is increased by macromolecular substances such as mannitol and fructose, which causes water in the tissues (including eyes, brain, cerebrospinal fluid, etc.
) to enter the blood vessels, thereby reducing tissue edema.

02 Pharmacokinetics Mannitol has a fast onset of action.
The effect of reducing intraocular pressure and intracranial pressure appears within 15 minutes after intravenous injection.
The peak time force is 30-60 minutes and lasts for 3-8 hours.

After intravenous injection, it is rapidly excreted by the kidneys, so under normal circumstances, the amount of metabolism by the liver is very small.

T1/2 is 100 minutes, and can be extended to 6 hours when there is acute failure.

When renal function is normal, 100g of mannitol is injected intravenously, and 80% of it is excreted through the kidneys within 3 hours.

The time that mannitol exerts the effect of lowering intracranial pressure and the peak of lowering intracranial pressure appear faster than glycerol fructose.
It is suitable for emergency rescue of large-area cerebral infarction, acute intracranial hypertension caused by cerebral infarction with hemorrhage, or critical situations of cerebral hernia.Glycerol fructose has a slower onset than mannitol, and its distribution in the body reaches equilibrium within 2-3 hours after intravenous administration.

Fructose has an energy-supplying effect.
It can provide 1339KJ of calories per 500mL.
It can enter the brain tissue through the blood-brain barrier and be oxidized into a phosphorylated matrix.
It is the only caloric source involved in brain metabolism, and its metabolic process does not require insulin.

Moreover, fructose is a simple sugar, which does not increase the amount of blood sugar and has an anti-ketone effect, so it can also be used by diabetics.

Glycerol fructose does not increase the burden on the kidneys, and enters the body to participate in metabolism, producing water and carbon dioxide.

It is suitable for chronic intracranial pressure increase, cerebral hydrocephalus, cerebral thrombosis, intracerebral hemorrhage and other encephalopathy.
It can more effectively improve the blood rheology state after cerebral infarction, and has the characteristics of improving microcirculation, safely and effectively reducing intracranial pressure[2] .

03 Adverse Reaction Table 2: Comparison of the adverse reactions between mannitol and glycerol fructose.
It can be found that the incidence of adverse reactions of glycerol fructose is significantly lower than that of mannitol, which is not easy to cause water and electrolyte disorders, and renal function damage is significantly lower.
Mannitol.

Therefore, for patients with renal impairment, elderly patients and patients with cardiac insufficiency, the use of glycerol fructose is more advantageous than the use of mannitol.

Summary: In summary, mannitol is cheap and has a fast onset, a single dose is large, and it is prone to kidney damage; glycerol and fructose alone have a slow effect on lowering intracranial pressure, and the effect is long and costly.

At present, the two are used interchangeably in clinical practice.
Many studies have shown that [3,4]: The combination of glycerol fructose and mannitol is used to treat intracranial hypertension.
The combined effect of the two can quickly reduce intracranial pressure, improve symptoms, and reduce the burden on the kidneys.
Protect kidney function, reduce the occurrence of electrolyte disturbances, but also overcome the rebound phenomenon of intracranial pressure of mannitol, and improve the safety of clinical medication. Reference materials: [1] Gao Chao, Huang Jietao, Xie Yanfeng, Shi Quanhong.
Meta analysis of mannitol combined with glycerol fructose in the treatment of cerebral hemorrhage[J].
Chongqing Medical Journal,2015,44(32):4541-4543.
[2] Liming Li, Song Wei,Hu Hankun,Liu Ping,Liu Weizhi,Li Ling.
Meta analysis of the efficacy and safety of glycerol fructose injection versus mannitol injection in the treatment of cerebral edema[J].
China Pharmacy,2014,25(44):4140-4143.
[3] Qian Liwei, Shi Honglei, Hong Li, Yang Yancheng, Wang Xuejing.
Analysis of the application effect of glycerol fructose combined with mannitol on intracranial infection in children with intracranial infection [J].
Chinese Journal of Nosocomial Infection, 2016, 26 (14): 3328-3330.
[4].
The efficacy and safety analysis of mannitol combined with glycerol fructose in the treatment of cerebral hemorrhage and cerebral edema[J].
Northern Pharmaceutical Sciences,2019,16(05):167-168.