Acclimatization on Kilimanjaro is the process in which an  individual organism adjusts to a gradual change in its environment . So  while your climbing  Kilimanjaro your body undergoes a process of trying  to  adapt the altitude transformation. 

So, physiologically, what happens during acclimatization is, as you ascend higher into the atmosphere, there is less atmospheric pressure pushing all the air molecules together, so oxygen molecules become few and far between.

Walk Slowly (pole pole) 
When you climb Kilimanjaro, you will hear the phrase ‘Pole, pole’. This  means ‘slowly, slowly’ in Swahili. The best way for your body to adapt  to altitude is to move really slowly. This allows the intelligent body to  adapt to the effects of altitude on Kilimanjaro. The higher you climb  the higher the altitude and the harder it takes your body to cope up  with its environment. 

Hydration
Drinking allot helps and its renown to be one of the BEST method while dealing with acclimatization. We recommend at least  drinking 4-5 Liters of water a day while climbing Kilimanjaro. It is  usually good to keep an eye on your urine; if it gets too dark, you need  to drink more. 

Climb high sleep low
Another practice  is   “Climb high; sleep low.” What this means is that  you should do day hikes that gain significant altitude, s and then  return to sleep and recuperate at lower altitudes. 

Avoid tobacco and alcohol and other depressant drugs  including, barbiturates, tranquilizers, and sleeping pills. These  depressants further decrease the respiratory drive during sleep  resulting in a worsening of the symptoms. 

Eat nutritious rich food
Eat a high carbohydrate diet (more than 70% of your calories from carbohydrates) while at altitude. 

In case you notice altitude symptoms. 
If you begin to show symptoms of moderate altitude illness, don’t go higher until symptoms decrease. (in fact, you should go to a lower elevation until you feel better). 

Diamox (Acetazolamide) allows you to breathe faster so that you metabolize more oxygen, thereby minimizing the symptoms caused by poor oxygenation. This is especially helpful at night when respiratory drive is decreased. Since it takes a while for Diamox to have an effect, it is advisable to start taking it at least 24 hours before you go to altitude and continue for at least five days at higher altitude. While taking Diamox Possible side effects may occur and they include tingling of the lips and fingertips, blurring of vision, and alteration of taste. The side effects subsides when the drug is stopped. 

WE HIGHLY RECOMMEND Contacting your physician for a  prescription. Since Diamox is a sulfonamide drug, people who are  allergic to sulfa drugs should not take Diamox. Diamox has also been  known to cause severe allergic reactions to people with no previous  history of Diamox or sulfa allergies. 

Dexamethasone (a steroid) is a prescription drug that  decreases brain and other swelling reversing the effects of AMS. Dosage  is typically 4 mg twice a day for a few days starting with the ascent.  This prevents most symptoms of altitude illness. 

WE HIGHLY RECOMMEND  Contacting physician for  prescription because of possible serious side effects. It may be  combined with Diamox. No other medications have been proven valuable for  preventing AMS.