First of all, there is no other option for treatment of ventricular fibrillation other than defibrillation. Without defibrillation, the heart continues to be in a state of cardiac arrest and it is difficult to maintain adequate circulation just by chest compressions (cardiopulmonary resuscitation or CPR). So defibrillation is a life saving procedure for which no other options exist. Since defibrillation involves the delivery of a high voltage shock, multiple high voltage shocks can cause some damage to the heart muscle, which can manifest as elevation of heart muscle enzymes in the blood and ST segment elevation on the ECG. Some transient suppression of the cardiac rhythm requiring back up pacing in case of an implantable defibrillator shock are also common. But by and large defibrillation is a safe procedure, which is life saving. In case of implantable defibrillators, frequent shocks may decrease the quality of life because some persons become afraid of shocks at unexpected times. This can be taken care of by good counselling which involves explanation of the fact that each shock is an opportunity gained for prevention of potential loss of life otherwise.
Only situation where the shocks are really are a disadvantage are the inappropriate shocks which can occur with an implantable defibrillator (ICD) sometimes, due to false sensing of an abnormal shockable rhythm when actually there is none. These inappropriate shocks can be reduced to a large extend by appropriate programming of the ICD.