The invention relates generally to novel pharmaceutical methods for the treatment of various conditions. Compositions comprising: at least one phosphodiesterase-5-inhibitor in combination with one or more of the following medications: a selective serotonin reuptake inhibitor; a serotonin-norepinephrine reuptake inhibitor; a cholinesterase inhibitor; a dopamine agonist; or a medication suitable to increase the chemical concentrations of the neurotransmitters, selected from amino acids, monoamines, neuropeptides and other agents capable of primary neurotransmission in the synaptic clefts, and their use for treating a neurodegenerative disease in a subject. The invention also relates to: Compositions comprising: at least one phosphodiestersa-5-inhibitor in combination with one or more of the following medications: a selective serotonin reuptake inhibitor; or a cholinesterase inhibitor, and their use for treating damaged skin in a subject.